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CHYMIST 



APPLIED T 



AGR IC UL 




By JOHN ANTONY CHAPTAL, 

C017NT OF CHANTELOUP. PEER OF FRANCE, MEMBER OF THE INSTITUTE, &r. 

TRANSLATED FROM THE SECOND FRENCH EDITION. 



Omnium rerura, ex quibus aliquid acquiritur, nihil est agricnltura melius, nihil 
uberius, nihil dulcius, nihil libero homine dignius. — Cicero. 

Good husbands will find the means, by good husbandry, to improve their lands ; 
but it will not be amiss that they be put in mind thereof, and encouraged 
in their industries. — Lord Bacon. 



BOSTON : 
HILLIARD, GRAY, AND CO 

1838. 



S5«S 



.CAT 



Entered according to act of Congress, in the year one thousand 
eight hundred and thirty-five, by Hilliard, Gray, and Co., in the 
Clerk's office of the District Court of the District of Massachusetts. 






V 



^-%w. 



STEREOTYPED AT THE 
BOSTON TYPE AND STEREOTYPE FOUNDRy. 




ADVERTI 



In offering to the public the following treatise the 
publishers believe that they shall render an acceptable 
service to the agricultural interest, the most important 
interest, of the United States. 

The author, one of the most eminent chymists of the 
age, was at the same time a practical agriculturist, own- 
ing large estates, which were for a long time cultivated 
under his personal direction. "In order," says he, " to 
make a useful application of the sciences to agriculture, 
it must be profoundly studied, not only in the closet, but 
abroad in the fields." By pursuing this method he was 
able to describe processes, and set down the course and 
the results of his large experience, with a fulness and 
clearness, that make them immediately available to the 
practical farmer. '' In my explanations," he remarks, 
*' I may sometimes have fallen into error, but I do not 
believe that I have misstated a single fact." 

The only work of note in the English language on the 
subject of Agricultural Chymistry is that of Davy, which 
was published in the year 1813. It consists of eight 
lectures delivered annually for ten years before the 
Board of Agriculture. In his preface he observes, that 
the rapid advance of chymical science obliged him to 
vary them each year they were delivered, and to alter 
them still further when preparing them for the press. 

Ten years afterwards, in 1823, appeared the first edi- 
tion of the present work, in which the author says, '^ The 
celebrated Davy has already published an Agricultural 



IV ADVERTISEMENT. 

Chymistry, and I have derived from it important princi- 
ples. Others will do better than we have done." But 
no one came forward to verify this prediction, and, in 
18-29, Chaptal published a second edition, increased by 
several new chapters and a copious Index. To this, the 
author's last edition, the present translation is con- 
formed.* 

Although the work was more especially intended for 
France, the larger portion of it is applicable to all coun- 
tries ; and those chapters, which at first view seem to 
have only a local interest, abound in hints which may 
anywhere be turned to account. 

And not only is the husbandman taught how to pro- 
duce, but the housekeeper also how to preserve, and 
enjoy in perfection, the various products of agricultural 
labor. 

The opinions of Chaptal on political science were 
in harmony with the institutions of the United States. 
He was an advocate for breaking up the large domains of 
France into small firms, which should gradually be pur- 
chased bv those who succeeded in cultivatini]^ them. 
He sought to raise the peasantry of his country from their 
ignorance and degradation to the condition of " indepen- 
dent farmers," in the American sense of the term ; to 
make them feel the intrinsic dignity of their employment 
while practising the most important of all arts, that which 
lies at the very foundation of civil society. To this end 
he wrote the present work, which sheds all the light of 
modern science upon the humblest details of rural labor ; 
and, while it increases the productive skill of those who 
are engaged in practical husbandry, at the same time 
" advances them in the dignity of thinking beings." 

* Chaptal died on the 29th of July, 1833, in his 76th year. 




CONTE 



INTRODUCTION . . .... xi 

CHAPTER I. 

General Views of the Atmosphere, considered in 

ITS Effects upon Vegetation .... 1 

Article 1. Of the Ponderable Fluids contained in the 

Atmosphere 2 

2. Of the Imponderable Fluids contained in 

the Atmosphere 8 

CHAPTER fl. 

Of the Nature of Earths, and their Action upon 

Vegetation . . 14 

Article 1. Of Mould 15 

2. Of the Nature of Soils . . . .18 

3. Of the Formation of Arable Lands . . 19 

4. Of the Composition of Arable Lands . . 24 

5. Of the Properties of the different Earths . 30 

6. Of the Properties of Mixed Earths, and 

the Methods of rendering them capable 

of a good Cultivation . ... 38 

7. Of the Analysis of Arable Soils . . 44 

CHAPTER IIL 
Of the Nature and Action of Manures . . .49 

Article 1. Of Nutritive Manures . . . .50 

2. Of Stimulating Manures , ... 66 



▼1 CONTENTS. 

CHAPTER IV. 
Of Germination 77 

CHAPTER V. 

Of the Nourishment of Plants 80 

Article 1. The Influence of Carbonic Acid upon Nu- 
trition 80 

2. The Influence of Oxygen Gas upon Nutri- 

tion 82 

3. The Influence of Air upon Fruits . . 85 

4. The Influence of Water upon Nutrition . 89 

5. Of the Effects of the Nourishment of Plants 

upon the Soil 92 

6. Summary of the Changes produced in Plants 

by Nourishment 99 

CHAPTER VL 
Improvement of the Soil 106 

CHAPTER VII. 

Of the Succession of Crops 120 

Principle 1. All plants exhaust the soil . . . 121 

2. All plants do not exhaust the soil equally . 121 

3. Plants of different kinds do not exhaust 

the soil in tlie same manner . . . 123 

4. All plants do not restore to the soil either 

the same quantity or the same quality of 
manure 124 

5. All plants do not foul the soil equally . 124 

CHAPTER Vni. 
View of the Products of French Agriculture . 131 



CONTENTS. 



Vll 



CHAPTER IX. 

Of the Nature and Uses of the Products of Vege- 
tation 132 

135 
136 
140 
141 
143 
147 
149 
154 
157 
159 
168 



E 1. 


Gum and Mucilage 


2. 


Starch or Fecula 


3. 


Sugar 


4. 


Wax . 


5. 


OUs . 


6. 


Resin 


7. 


Vegetable Fibre 


8. 


Gluten and Albumen 


9. 


Tannin 


10. 


The Vegetable Acids 


11. 


The Fixed Alkalies 



CHAPTER X. 

On the Preservation of Animal and Vegetable 

Substances 182 

Article 1. On the Preservation of the Fruits of the 

Earth by Drying 183 

2. On the Preservation of the Fruits of the 

Earth by Secluding them from the Ac- 
tion of Air, Water, and Heat . . 188 

3. On the Preservation of certain Articles of 

Food by means of Salt and Spirituous 
Liquors 200 

CHAPTER XI. 
On Milk and its Products 207 

Article 1. Of Cream 209 

2. Of Butter 210 

3. Of Caseous, or Cheesy, Matter . . . 214 



Vlll CONTENTS. 

CHAPTER XII. 

Comparison between an Agricultural and a Manu- 
facturing Nation 221 

CHAPTER Xni. 
On Large and Small Estates 224 

CHAPTER XIV. 

The Encouragement which ought to be given by 

the Government to French Agriculture . . 232 

CHAPTER XV, 
Ok Fermentation 238 

CHAPTER XVI. 
Ok Distillation ........ 252 

CHAPTER XVH. 

Osr THE Means of preparing Wholesome Drinks for 

THE Use of Country People .... 271 

CHAPTER XVni. 

Op Farm Buildings, both for Men and Animals, and 

the Means of Making them Healthy . . . 283 

CHAPTER XIX. 
On V^ashing, Bleaching, &c. 289 

CHAPTER XX. 

On the Cultivation of Woad, and the Extraction 

OP Indigo from it 294 



CONTENTS. IX 

Article 1. On the Cultivation of Woad . . . 295 

2. Preparation of Woad Cakes . . . 297 

3. The Extraction of Indigo from Woad . 302 

CHAPTER XXI. 

On the Cultivation of the Beet Root, and the Ex- 
traction OF Sugar from it 315 

SECTION I. On the Cultivation of the Beet Root . . 315 

Article 1. On the Choice of Seed .... 316 

2. On the Choice of Soil . . . .317 

3. On the Preparation of the Soil . . . 318 

4. On the Manner of Sowing Beet Seed . 319 

5. On the Care required by Beets during 

their Vegetation 320 

6. On the Gathering of Beet Roots . . 321 

7. On the best Method of Keeping Beet Roots 322 

SECTION II. On the Extraction of Sugar from Beets 324 

Article 1. On the Preparation of the Roots . . 324 

2. On the Method of Rasping the Beet Roots 325 

3. On the Extraction of the Juice . . . 325 

4. On the Purification of the Juice . . 327 

5. On the Concentration or Evaporation of the 

Purified Juice 330 

6. On Boiling the Sirup . . . .331 

7. On Boiling the Molasses and Leaching 

Sirups 336 

SECTION in. On the Refining of Sugar obtained from 

Beet Roots 337 

Article 1. On Clarification 338 

2. On Whitening Sugar .... 339 

SECTION IV. On the Distillation of Molasses . . 345 

SECTION V. On the Products of a Sugar Manufactory 348 



X . CONTENTS. 

Article 1. Of the Product in Sugar .... 848 

2. Of the Secondary Products ... 349 

3. On the Value of the Products . . . 349 

SECTION VI. On the Expense of a Sugar Manufactory 351 

SECTION VII. General Considerations . " . 354 



^^ RECEIVED ^< 

INTRODUCTION. 



Without agriculture, men would live wandering and 
unsettled lives, disputing with each other for the posses- 
sion of such animals as they could make their prey, 
and for the spontaneous fruits of the earth. They would 
have no bond of society, nor country. 

By multiplying the resources for food, agriculture has 
permitted men to unite themselves into communities for 
mutual assistance. Whilst some cultivate the land, to in- 
crease its productions, others apply themselves assiduously 
to furnishing society with the necessary implements of in- 
dustry. It is thus that, by reciprocal intercourse and ex- 
changes, commerce has been established, and civilization 
extended. 

If living in cities, and leading the sedentary life required 
by the practice of many of the arts, have softened and 
enervated a portion of the human species, agriculture has 
preserved the inhabitants of the country in a state of 
health, strength, and good morals. Nor is it one of the 
least blessings which it bestows upon society, that it 
thus continually repairs that portion of it which would 
otherwise become degenerate. 



XU INTHODUCTION* 

Amongst all nations, agriculture is the purest source 
of public prosperity. Situated under different climates, 
their productions and modes of cultivation are extremely 
diversified. But commerce scatters the productions of 
the various soils ; and thus each nation is able to enjoy 
the fruits pecuUar to the several portions of the earth. 
These exchanges have connected nations together, by 
rendering them dependent on each other ; and the advan- 
tages arising from intelligence and industry have been 
made to spread through all. 

The agriculturist, then, holds the first rank amongst 
men. By what fatality has his condition, in France, 
been always miserably servile and degraded ? Those, 
even, whom he has toiled to support in luxury and idle- 
ness, have often compelled him to envy the condition of 
the animals which assist him in his labors. The statute 
work, the tithes, and the other exactions of feudal power, 
have left him, for his subsistence, only the most wretched 
productions of his fields. He has watered the land with 
the sweat of his brow, but the fruits which it brought 
forth were for the enjoyment of others. In this state of 
misery and oppression, the cultivator of the soil followed 
blindly the track which was marked out for him. Without 
emulation, without knowledge, and nearly without inter- 
est, the thought of improvement scarcely presented itself 
to his mind. 

It was not till the moment, when, by a wise return to 
the true principles of justice, the right of property was 
respected and received protection, — when taxes were 
proportionably levied, and privileges abolished, — that the 
farmer recognised his strength, and felt himself rising 
into the true importance and dignity of his state. Then, 



INTRODUCTION. Xlll 

intelligence was extended to the business of the fields ; 
the means of ameliorating the soil, and improving its pro- 
ductions, were established and increased ; and private in- 
terest was for ever united to the public good. At that 
period, agriculture took a new impulse ; and since then, 
its progress has been rapid. The nature of soils has 
been better known ; the cultivation of artificial meadows 
has been extended; and a rotation of crops has been 
established upon principles recognised in all those coun- 
tries, where agriculture has made the most progress. 
The number of domestic animals has also progressively 
increased, and, with them, the manures and the labors 
which form the basis of agricultural prosperity. 

It remains to us, at this day, to improve agriculture by 
the application of physical science. All the phenomena 
which it presents, are the consequences necessarily re- 
sulting from those eternal laws by which matter is gov- 
erned ; and all the operations which the agriculturist per- 
forms, serve only to develope or modify these laws. It 
is, then, to the acquisition of a knowledge of these laws, in 
order to calculate their effects and modify their action, 
that we ought to direct all our researches. 

Can an»y study present to the agriculturist more attrac- 
tions, than that, which has for its object the explanation 
of those effects, which every day captivate his senses 
and astonish his reason ? Without doubt, observation 
has made him acquainted with the uniform march 
of nature. In all her operations, he can judge of the 
modifications effected in her productions by the state 
of the atmosphere, the variation of climate, and the 
nature of the soil. Even this practical knowledge en- 
ables him to direct many of the labors of the field. 



XIV INTRODUCTION. 

But, if he be permitted to ascend from the effects to 
their causes ; if we can determine, and demonstrate to 
him, the action which is exercised upon vegetation by 
the air, water, heat, and hght, the sun, various kinds 
of manure, he. &tc., and assign to each of these agents 
the part which it performs in these grand phenomena, 
bow much will he be moved I Even whilst an igno- 
rant witness of these wonders, he is lost in admiration 
of them : but, more enlightened, he will feel this sen- 
timent constantly increasing, as he rises to the causes 
which produce them. 

Convinced that we must look, for farther improve- 
ments in agriculture, to the application of the physical 
sciences, I think it proper here to establish some general 
principles, the more complete developeraent of which 
will be found in this work. 

The laws of nature are eternal and unchangeable. 
The natural 'state of bodies, their respective situations, 
the changes which they undergo, the phenomena of 
decomposition and of composition, which animate the 
whole surface of the globe, are the results of these laws. 

We see, everywhere, that matter is governed by two 
general laws ; by the power of which all bodies exist in 
their natural state. The first is exercised upon masses 
of matter ; the second, upon those molecules of which 
masses are composed. The one is the general law of at- 
traction, or gravitation; the other, the law of affinity, 
or chymical attraction. 

The law of affinity (the only one of which I shall now 
speak) tends constantly to draw together the particles 
of which bodies are composed. If this force acted 
alone, the degrees of density exhibited by bodies in their 



INTRODUCTION. XV 

natural state would depend entirely upon the degrees of 
affinity existing between their component particles. But 
its action is balanced and modified by that of the fluid of 
heat, which enters, in various proportions, into all sub- 
stances, and which tends to separate, one from another, the 
elements which affinity draws together. Affinity, alone, 
would form only solid masses, inactive, and more or less 
compact. The action of heat, alone, would produce only 
gases, or aerial substances. But the combined action of 
these agents presents to us bodies either in a solid, liquid, 
or fluid state, according to the degree of intensity with 
which one or the other force acts upon the component 
parts. The natural state of bodies, then, is owing to the 
combined action of the law of affinity, which brings their 
particles into union, and the interposing fluid of heat, 
which separates them from each other. 

The variations which the atmosphere undergoes during 
the different seasons of the year are sufficient to produce 
changes of consistency in some bodies. Water, for in- 
stance, is either solid, liquid, or aeriform, according to the 
temperature of the air. 

Man, who governs the power of heat at his pleasure, 
can produce all these remarkable changes in the natural 
state of bodies. He can augment or diminish their con- 
sistency at his will, and cause them to assume either the 
solid, liquid, or gaseous form, according as he adds or 
takes away that fluid. 

The changes produced by the addition or subtraction 
of heat are not permanent. The body returns to its 
natural state, the moment the cause has ceased to 
operate, — imparling to the surrounding substances the 
excess of fluid it has imbibed, or receiving from them 



XVI INTRODUCTION. 

that of which it has been deprived. These aherations 
of form and consistency do not affect the nature of 
bodies; but, by bringing into contact or separating the 
molecules of which they are composed, they augment 
or diminish their cohesion and their affinity, and thus 
dispose them to form new combinations. 
. Tlie principles which I have just explained are not 
rigorously applicable to animal and vegetable substances, 
nor to some other compound bodies, except so far as 
the effects of a low degree of heat are concerned. The 
constituent principles of such bodies do not all require 
the same degree of heat to cause them to pass to the 
liquid or gaseous state. It follows, then, that some of 
them can take the one or the other of these forms, by any 
degree of heat above that of the atmosphere, and thus 
be separated from those which remain fixed. In this 
case decomposition is produced. 

If the force of affinity were the same amongst all the 
elementary particles of which various bodies are com- 
posed, there would be only confused aggregations of 
matter, throughout all the operations of nature and art. 
But each element has its peculiar affinities, which enable 
it to enter, more or less closely, into combination with 
certain other elements, whilst it strongly resists a union 
with those for which it has no affinity. All matter is 
formed, governed, and separated, according to these 
different affinities. The uniform reproduction of the 
combinations of art and the productions of nature is 
derived from this principle. 

It follows from the preceding statement, that the force 
of affinity alone can hold in lasting combination the par- 
ticles of matter, — and that bodies are, even then, liable 



INTRODUCTION. XVU 

to decomposition ; for, according to the laws of elective 
affinity, one constituent of a compound body will forsake 
another, for which it has a certain degree of affinity, to 
unite itself with a third, for which its affinity is stronger. 
We thus see how important it is, for those who wish to 
study the operations of art and nature, to be acquainted 
with the degrees of affinity that exist amongst the various 
elementarv bodies which enter into combination. Whilst 
the chyraist influences, according to his will, nearly all 
the agents which are employed by nature, she can follow 
him in her labors, even when she cannot imitate him in 
her productions. She knov^^s the materials which the 
chymist employs, and can often furnish them to him, and 
facilitate his operations. She can foresee his mistakes, 
and cautiously turn aside the causes which would pro- 
duce them. In a word, the mutual action exercised by 
bodies is constantly regulated by the immutable laws of 
nature. But the chymist can at pleasure dispose of these 
same bodies of which he knows the respective affinities. 
He can combine them in all their proportions, submit 
them to all degrees of heat, and subject them to the 
action of external agents, the energy of which he can 
increase or diminish to almost any extent, and thus 
produce results which nature, in her constant and unde- 
viating march, cannot give rise to. It is by means of 
this power, that chymistry forms, every day, new com- 
positions, and that she has enriched industry and econo- 
my with a vast variety of productions, which, without 
the assistance of this science, v/ould have been for ever 
unknown. 

Rude and inorganic matter obeys no other laws than 
those of which I have spoken. All the changes which it 

B 



XVUl INTRODUCTION* 

experiences, all the phenomena which it presents, all the 
combinations and decompositions which take place in it, 
result from them. Chymistry can foresee and explain 
the consequences of their action. She can even pro- 
duce, by her exertions, new combinations. 

In addition to the laws of affinity, which govern inor- 
ganic matter, living bodies are subject to other laws, 
which continually modify the action of the first. These 
laws of vitality are energetic, and govern the law of 
affinity in proportion to the perfect organization of the 
body. It is this, which causes the mode of action in Hving 
bodies to escape our researches ; so that, although wit- 
nesses of all which passes in these bodies, we can neither 
explain nor imitate their productions. The science of 
chymistry is limited to a knowledge of the substances 
which enter into animals and vegetables, to serve them 
for nourishment ; and to the study of all the agents 
which aid them in the performance of their functions. 
She knows what these bodies appropriate to their use, 
and what they reject. But the mode of elaboration 
by their organs, the formation of their products, and the 
manner of their growth, is, and must for a long time be, 
a mystery to us. That which we already know of the 
functions of living bodies, is much ; but that of which we 
are ignorant, far exceeds it. 

The laws of vitality, like all the other laws of nature, 
are unchano;eable. But their action is varied in livins 
bodies by a difference in organization ; in the same 
manner as the products vary in each species, and in 
each one of their organs. It is this variety of productions 
which surprises us, — especially when we consider, that 
their form and their quality are constantly renewed every 
year, and with every generation. 



INTRODUCTION. XIX 

These laws of organization have, then, set the 
bounds, over which science has not yet been able to 
pass. She has, however, opened to our view some sub- 
lime pages of the book of nature ; and she has made 
many and useful applications of their contents. 

The living plant, fixed by its root to an immovable soil, 
has no power of motion to enable it to seek its support 
from distant substances. It derives all its nourishment 
from the earth and air by which it is surrounded. These 
aliments are elaborated in the organs of the plant. They 
are there decomposed and combined with its elements, 
in a regular and uniform manner. With the dead plant, 
the case is widely different. Upon that, other bodies 
exercise an action entirely physical. When organization 
ceases to modify their effects, the same agents, such as 
air, water, and heat, which assisted it in performing its 
functions whilst living, concur powerfully in decompos- 

# 

ing it when deprived of vitality ; and complete disorga- 
nization can only be prevented by secluding it entirely 
from the contact and action of these bodies. 

It is at this period, that cbymistry can exercise its 
powder with full effect. She knows the elements that 
enter into the composition of the dead plant ; she knows 
the various degrees of affinity by which they are united, 
and can predict with certainty the changes which will 
follow from the action of those external agents, which 
she can modify at her will. 

From the observation of these circumstances, it is my 
opinion, that the knowledge of cbymistry can, with ad- 
vantage, be applied to the labors of the agriculturist. I 
believe, that, by a better acquaintance with the bodies 
subject to his management, by uniting well-established 



XX INTRODUCTION. 

facts to a sound theory, by determining with care the 
effects of all those bodies which can exert any influence 
upon vegetation, and the modes of their action, we shall 
be able to deduce principles, the application of which 
will greatly accelerate the progress of the most impor- 
tant of our arts. 

All the sciences have a natural course from which 
they never deviate : they begin by collecting and prov- 
ing facts ; and when these facts are well established, they 
compare them with each other, and deduce from them 
principles of general application. 

The facts in agriculture are already numerous ; but 
have the modifications wrought by the nature of the 
soil, the action of manures, the state of the atmosphere, 
the influence of chmate, and the varieties of exposure, 
been sufficiently attended to? Will a fact observed in 
one place be constantly reproduced in another ? Since 
such is not the case, we must necessarily come to the 
conclusion, that solitary facts are not sufficient to estab- 
lish principles in agriculture. It is necessary that they 
should have been observed and verified, under the in- 
fluence of all the agents of which I have spoken ; and 
that we should know the modifications which each one 
produces, in order to be able to draw from them general 
and practical consequences. If the agents of vege- 
tation were constantly the same, if their effects were 
everywhere the same, one fact alone would be sufficient 
to establish a principle, applicable to all localities ; but 
the difference of their action under different circum- 
stances necessarily produces important changes in their 
results : and this it is, that causes the kind of agriculture 
which prospers in one country, to be unsuccessful in an- 



INTRODUCTION. XXl 

Other ; and an agriculturist, who wishes to try methods 
of cuUivation which have succeeded elsewhere, often 
finds himself deceived in his expectations, because he 
cannot unite the same circumstances to ensure success. 

I have thought that a work upon the principles of ag- 
riculture, which should make known the properties and 
actions of the several agents which influence the results 
of its operations, would be really useful ; and accordingly 
I have applied myself to forming an acquaintance with 
the most usual methods of cultivation, in order that I 
might extend the application of them to other cases to 
which they might be suited. 

But it is not sufficient to enlighten the agriculturist, in 
order to facilitate the progress of the art ; the government 
has an important duty to perform towards it. It is only 
when intelligence and encouragement are united, that 
the farmer can be assured of lasting prosperity. 

Agriculture is the most fruitful source of the riches 
of a country, and of the welfare of its inhabitants ; and 
it is only as the state of agriculture is more or less flour- 
ishing, that we can judge unerringly of the happiness of 
a nation, or of the wisdom of its government. The pros- 
perity which a country derives from the industry and 
skill of its artisans, may be but a passing gleam ; that aione 
is durable, which has its rise in a good cultivation of the 
soil. These facts ought to be constantly present to the 
mind of the government, and to influence all its measures. 

A government awake to its true interests will seek to 
facilitate and increase the cultivation of the soil, and to 
open new channels for the disposal of its products. It 
will protect property, by causing its rights to be re- 

B* 



XXll INTRODUCTION. 

spectedj and punishing breaches of the laws concerning 
it ; and it will guarantee the proprietor against arbitrary 
exactions. The taxes should be regulated in such a 
manner as to take from the agriculturist only a portion 
of the increase arising from his labors ; for, if he have 
no surplus over his immediate wants, there will remain 
to him neither the means of improving his modes of cul- 
tivation, nor of supporting his family with comfort ; 
neither will it be possible for him to renew his stock of 
domestic animals, nor to augment their number. Any 
government which does not leave to the farmer a 
great part of the profits proceeding from his harvests, 
soon puts a stop to the production of them, and thus real- 
izes the fable of the goose with golden eggs. 

By encouraging improvements in agriculture, and fa- 
voring the increase of production, government enriches 
the agriculturist less than its own revenues ; since by 
these means the quantity of taxable matter is increased, 
and the right of government recognised under all its 
forms, whether the article produced be employed in its 
crude state for domestic use, or whether it furnish the 
workshop of the artisan with the materials of his handi- 
craft. 

Though the territorial imposts have been much dimin- 
ished within a few years, they are still far too high for the 
prosperity of agriculture. A bad harvest, a mortality 
amongst the animals upon a domain, or a prevailing ep- 
idemic, exhausts the scanty store which the economy of 
the farmer had enabled him to reserve from a favorable 
season ; and thus the greater part of them are forced 
to contract debts. A succession of abundant harvests 



INTRODUCTION. XXlll 

hardly enables them to repair the loss sustained from the 
calamities of a }ear. The peasant, everywhere, lives 
only from day to day, because he has no capital, and 
his poverty does not pennjt him either to provide 
against or repair a misfortune. 

The government of this country has been often occu- 
pied with the project of clearing those wild lands of 
which a part of it consists ; it has even made some at- 
tempts, and been at some expense, to carry these plans 
into execution. It would have been wiser to excite and 
encourage the improvement of those lands already under 
cultivation ; and by this course the best results would 
infallibly have been obtained. These enterprises, in a 
country where the cultivation of good land has not ar- 
rived at perfection, belong to the province of individual 
speculation, which never fails to execute them, provided 
it sees any chance of success. 

Agwculture has for a long time required a law, which 
should specially encourage improvements, and effect the 
clearing of uncultivated grounds ; this law should fix for 
the future, in a permanent and invariable manner, the 
taxes on land brought into cultivation, so that they never 
should be raised on account of their produce or the value 
which has been bestowed on them by labor and indus- 
try. The fear alone, that taxation will sooner or later 
be extended to improvements, is sufficient to turn the 
current of capital from that all-important employment, 
and to throw it upon those operations and speculations 
which, for the most part, employ property in ways that 
are of no advantage, either to the nation or to the gov- 
ernment. 



XXlV INTRODUCTlOlsr, 

Another law not less required by the interests of ag- 
riculture and society, is one having for its object the en- 
couragement of planting forests, and the preservation of 
those which now exist ; without some law to this effect, 
a future and not distant period threatens their entire de- 
struction. Without doubt private interest, more active 
perhaps in our day, the division of property, and the loss 
of great territorial fortunes, have prepared the way for 
and brought on these consequences ; but the law has con- 
tributed more than anything else to produce them. In 
fact a proprietor pays eveiy year a tax levied upon the 
trees of his domain, and it is easy for him to calculate, 
that it is more advantageous for him to fell those of 
twenty years' growth, than to leave them to attain the 
age of one or two centuries. 

A good law regarding district roads would be a great 
benefit to the inhabitants of the country ; easy transpor- 
tation by means of convenient roads is constantly re- 
paying to the farmer the expense which he must be at in 
making and preserving them ; since they will enable his 
cattle to perform the same quantity of labor at a much 
less expense of time and strength. But it is difficult to 
obtain from the administration these important local im- 
provements. The mayors, their assistants, and the 
members of the municipal councils, are generally the 
richest proprietors of a district ; and they never condemn 
themselves, either to restore to the public ways the en- 
croachments they have permitted to be made upon them, 
or to furrow their fields by roads, or to support nearly 
the whole expense which these labors for the public 
good would require. There should be attached by law 



INTRODUCTION. XXV 

to each department, a pupil of the School of Bridges 
and Highways, who, a stranger to any particular local in- 
terest, should lay out district roads, determine their width, 
compel each proprietor to confine his boundaries within 
their original limits, prepare plans and schemes, and 
prescribe the suitable materials to be employed in the 
execution of them. The labors of this engineer should 
be subject to the inspection of the engineer of the arron- 
dissement, and to the approbation of the chief engineer ; 
upon the report of this last, the prefect should order the 
proposed plans to be carried into execution. The com- 
munes should then provide for defraying the necessary- 
expenses, in such a manner as might be least burden- 
some, and present the result of their deliberations to the 
prefect for his approval. 

Canals and highways are for society at large what 
by-roads are for the separate portions of it. These 
grand means of communication may be called the arte- 
ries of the social body, conveying life through all its 
parts. One of our most profound writers has said, that 
" rivers and navigable streams are roads which travel ; " 
but canals present great advantages over navigable riv- 
ers ; they go to seek the productions of a country in the 
places of their origin ; their direction is always governed 
by the necessity of such means of intercourse ; their 
navigation is easy, regular, and safe ; they animate and 
give life to all the country through which they pass, with- 
out ever counterbalancing these advantages by the rav- 
ages of an inundation. 

By diminishing the expense of transportation, by 
opening communications with the distant portions of a 
country, by facilitating the exchange of articles, and 



XXVI INTRODUCTION. 

rendering common to a whole nation the production of 
each locality, all the sources of public wealth and pros- 
perity are multiplied. By an increased intercourse be- 
tween men civilization is perfected; intelligence and 
urbanity of manners find their way into the most se- 
cluded spots ; and the law which has established a great 
system of inland navigation in France, will excite the 
gratitude of all future ages. 

If agriculture requires some new laws favorable to 
her interests, she also demands the suppression of a 
small number which are opposed to them. The law 
should protect and favor exchanges ; and government 
ought to view in this operation only the mutual accom- 
modation arising to the proprietors of the property ex- 
changed, and not to collect any duties excepting from 
the profits on what is exchanged. By facilitating and 
encouraging exchanges government would do much for 
agriculture ; scattered and disjointed property would in- 
sensibly become collected around the dwelling of the 
owner ; the inspection of it would thus be rendered 
easy, and a better system of management might be 
adopted without difficulty ; transportation would be fa- 
cilitated and rendered less expensive : the laboring ani- 
mals would suffer less from fatigue, and their quantity 
of work be increased in value. 

Another advantage arising from the exchange of 
property is that of annexing to some estates small por- 
tions of land lying contiguous to them, which, from their 
limited extent, do not give scope to the exercise of all the 
resources of good husbandry. These exchanges would 
likewise have the good effect of extinguishing a thou- 
sand disputes, which are constantly arising amongst the 



INTRODUCTION. XXVU 

proprietors of real estate, about limits, usurpations, and 
encroachments. 

But the greatest benefit which o-overnment can confer 
on agriculture, is without doubt the suppression of the 
duty upon salt. During those years in which the sale 
of salt was free from duty, the borders of the Mediter- 
ranean were covered with salt-works ; immense capitals 
were employed in forming these establishments, and they 
sold salt to the amount of twenty millions of francs 
per year. The tax has given a death-blow to this beau- 
tiful scene of industry ; nearly all the salt-works are 
abandoned. The consumption of salt has been so much 
reduced, that the price of fifty kilogrammes (1 cwt.) 
is not above twenty-five centimes in the salt-pits ; and 
the duty upon as much salt as is sold for one million 
five hundred francs, produces to the treasury from forty- 
five to sixty millions. 

In order to realize all the evil which results to agri- 
culture from the duty upon salt, it is sufficient to know 
the extensive advantage arising from its employment. 

Salt is of the utmost importance to all ruminating ani- 
mals, increasing their relish for their insipid food, excit- 
ing the action of their membranous and weak stom- 
achs, and preventing those obstructions of the intestines 
which are produced by the use of dry forage during the 
winter. It is generally observed that those animals are 
preferred in the market, which have been habitually fed 
upon saline plants, and that their flesh is of a superior 
quality. There is no farmer, who has not been able to 
see the difference, at the close of a winter, between 
those animals which have received their supply of salt 
and those that have been deprived of it ; the first are well 



XXVlll INTRODUCTION. 

shaped, large, and fat ; their hair is glossy, their eyes 
lively, and their motions prompt and firm : the second 
present images of suffering and misery ; the sheep have lost 
nearly all their fleece before shearing time, and that which 
remains is falling from them in locks ; the neat cattle are 
lean and sickly, their organs of digestion are impeded 
in their action, and it is only after having browsed the 
juicy herbage of spring that they recover their health. 

During the time that salt was freed from any impost^ 
the use of it in agriculture became each year more ex- 
tensive ; it was mixed with manures, to increase their 
activity ; it was spread at the roots of trees, to reani- 
mate their languishing powers of vegetation ; and the 
quantity of salted provisions, both for market and for 
home consumption, was much increased. 

The impost upon salt is to agriculture a real calamity, 
since it has taken from it many of its sources of pros- 
perity ; and at the same time the public treasury has 
received no advantage from the tax, equal to the injury 
which it has inflicted upon agriculture. 

I know that in a well-organized state, the receipts 
ought to cover the expenditures ; and that it is not 
possible to repeal a tax of forty-five millions of francs, 
without replacing it by another equally productive ; but, 
in selecting objects for taxation, those ought to be taken 
which will fall least heavily on the interests of those 
who pay them ; and it must be prudent to avoid those 
which will lessen production, and check improve- 
ments in industry, conmierce, and agriculture. In 
establishing a tax it is likewise necessary to look for- 
ward and to reason upon the future effects of it ; 
a tax which will produce ten millions, may impover- 



INTRODUCTION. XXlX 

ish a nation more than one of fifty, and, beyond the 
amount of ten millions, become a scourge ; for, the 
government which stifles reproduction, opposes the de- 
velopement of industry, and, being reduced to live upon 
its capital, will very soon partake of the public poverty. 
By whatever impost the tax upon salt may be replaced, 
I doubt whether one can be found more injurious in its 
effects. All the complaints that are made in regard to 
the revenue ought to be directed against this duty ; 
and in order to hasten the suppression of it in the coun- 
try, the tax might be kept up on the consumption of 
the towns, where salt forms but a small part of the 
expense of each household. 

There is, at this day, much inquiry whether the divi- 
sion of landed property is favorable or injurious to agricul- 
ture. This division is the necessary consequence of the 
partition of successions in a direct line, and of the sale 
of detached portions of great estates. The question of 
the division of property has its supporters and its op- 
posers ; but I believe that it is from not having viewed 
the subject in its true light, that opinions in regard 
to it are still divided. Wherever labor is abundant ; 
wherever the cultivation of grain and of artificial fodder 
cannot be carried to its full extent ; wherever the nature 
of the soil admits only, or mostly, of the cultivation of 
the vine, there the division of property is advantageous. 
The impossibility of feeding animals for labor, in such 
situations, calls the arm of man into use to supply their 
place ; and the husbandry on a small scale thus prac- 
tised, fertilizes a soil, which would otherwise remain 
sterile. A small estate, placed in the hands of an in- 
dustrious and intelligent man, will always produce more 
c 



5vXX INTRODUCTION. 

than if it were annexed to an extensive domain. The 
children of the proprietor of a small farm will collect 
manure for the fields, or clear them from noxious 
weeds : the father of the family will till the soil with 
care, and at the most favorable seasons ; he will not 
leave a corner of his ground unproductive. Under this 
kind of management four or five acres of well-cultivated 
land is sufficient for the maintenance of a family ; whilst 
fifty, in a farm, the labors of which are carried on upon 
a large scale, requiring the assistance of animals, will 
scarcely support five or six. 

If we consider the division of property in its moral 
relations, we shall find its advantages greatly increased. 
The laborer without property has no country ; he remains 
fixed to no point excepting by habit ; his means of subsist- 
ence are everywhere, where he can employ his strength ; 
the laws are for him only modes of oppression ; disor- 
der and insurrection present to him some chance of 
ameliorating his condition, and he is always at the dis- 
posal of those who will pay him best. 

Landed property, whether it be extensive or not, by 
attaching the owner of It to the soil, causes him to love 
the government which protects it, and to respect the 
laws which guarantee its possession. Since the num- 
ber of proprietors of land in France has been tripled, 
the leaders of insurrection amongst the people have not, 
in the country, found any support. 

In a neighboring kingdom, where they count scarcely 
twenty-five proprietary families, and where manufacturing 
industry employs the greater part of the population, the 
governuient is obliged to levy a tax of nearly three hun- 
dred millions of francs^ ip order to give bread to the va- 



INTRODUCTION. XXXI 

grant portion of the community, and thus to secure the 
public tranquillity. In Spain, where the nobility and cler- 
gy possess nearly all the landed property, we see the pop- 
ulation besieging the gates of the castles and convents, to 
ask alms from the monks and nobles. Without doubt 
the greater part of the wealthy are not insensible to the 
cries of misery which surround them ; but it is surely 
better for each one to derive his subsistence from his 
own resources, than to beg it from another. I do not 
pretend, that it would be of advantage to divide all the 
French territory into small estates, or to reduce it every- 
where to the mode of culture adapted to them : those 
portions of country, which admit of the full develope- 
ment of great agricultural resources, ought to be covered 
with farms of an extent sufficient to unite all the means 
necessary to call them into action. It is not ex- 
pected that it will be possible, except on these great 
farms, to raise cattle, or to supply all the requisites of 
life for the markets. The present state of things has 
established itself by its own fitness : the difterence be- 
tween those portions of country suited to great, and 
those adapted to small cultivation, is so well felt, that 
the division of real estate into small farms is only found 
in the last. Private interest has placed the bounds of 
the subdivision of territory ; and it can be safely left to 
that great mover of the conduct of men, to stop the 
further division at that moment, when the processes of 
labor can be carried on with the most ease, and to the 
greatest advantage. If exchanges should become less 
difficult than at present, there is no doubt that contiguous 
portions of land, belonging to different proprietors, would 
be united under one, till a farm of convenient extent 
should be formed. 



XXXII INTRODUCTION. 

The progressive steps in agriculture are, and ought 
to be, slow ; and it is contrary to the counsels of wisdom 
and prudence, to wish to deviate fronri customs rendered 
sacred by time, until the new modes to be adopted 
shall have received the sanction of successful experi- 
ment. 

The reproach, which is every day made to the hus- 
bandman, of his indifference towards new modes of 
culture, appears to me not to be well founded ; he 
wishes first to see and compare them with the methods 
to which he has been accustomed ; he has neither the 
knowledge, nor the means of forming beforehand a just 
estimate, of the advantages which they offer him ; he 
perseveres then in his old course till some neighbour, 
richer and more enlightened than himself, is able to pre- 
sent to him, by the new mode, results more advanta- 
geous than he has obtained from his own. 

Example is the only lesson profitable to a husband- 
man ; when one is placed before his eyes, and his reason 
is convinced of its goodness, he is not slow to follow it ; 
and by no other way than this, can improved methods 
of agriculture be introduced and propagated. 

The civil discords which have so long agitated France, 
have compelled a great number of proprietors to aban- 
don the stormy life of the city, and to establish them- 
selves in their domains, where they direct the labors of 
their farms ; agriculture is thus enriched by the intelli- 
gence, the wealth, and the scientific views, which they 
carry with them to every part of the country. It is 
much to be desired that this course should be generally 
pursued, since it cannot but have a happy effect upon 
agricultural prosperity, and thus ultimately benefit the 
kingdom at large. 



INTRODUCTION. XXXlU 

Without doubt the superintendence of the labors on 
an extensive domain, by an enlightened owner, is bene- 
ficial to the advancement of agriculture ; and at the 
same time that it is one of the most useful, it is one of 
the most delightful and noble of all occupations ; but 
if the improvements, which the proprietor of a large estate 
can introduce, do not compensate for the advantages 
which the small proprietor or farmer has over him, the 
former may sacrifice his interests. The proprietors of 
small farms are constantly at the head of the laborers, 
and themselves assist in the performance of the work ; 
they live at small expense, attend fairs and markets 
frequently, and buy and sell to advantage ; they have 
no overseers to pay, nor to feed ; their wives and daugh- 
ters take care of the poultry-yard and dairy, and per- 
form the labors of the house ; such are happy, when, at 
the end of a year, they find some profit arising from the 
labors of themselves and families. The large proprie- 
tors, whose possessions are intrinsically of greater value, 
do not enjoy any of these advantages ; and, if they do 
not compensate for the absence of them by the exer- 
cise of a superior kind of industry, they must sustain 
loss, where the husbandman derives gain. In order to 
ensure success in any undertaking, it is not sufficient to 
adopt a new method of proceeding. In agriculture, as 
in every well-conducted enterprise, every thing should 
be calculated, and the operations to be entered upon 
should be regulated by a comparison of an estimate of 
the expenses attending them, with an estimate of the 
profits which may be rationally expected to arise from 
them. Though a paradoxical statement, it is certainly 
true, that a farmer may be ruined by a good harvest j 
c* 



XXXIV INTRODUCTION. 

and it is equally as true, that agriculture does not re- 
quire unnecessary expenses ; on the contrary, she con- 
demns every superfluity as a species of luxury. It is 
from their not being fully impressed with the impor- 
tance of these principles, that we every day see new 
proprietors condemn, almost without examination, usages 
consecrated by time and accredited by good results, to 
introduce, at great expense, innovations unsuited to the 
soil or climate. Being unable to bring these into coope- 
ration with their plans, they are obliged to abandon their 
estates after having ruined their fortunes. 

One of the causes, undoubtedly, which contributes most 
to retard the application of just principles to French ag- 
riculture, is the shortness of the leases ; which hardly al- 
lowing a farmer to become acquainted with the nature of 
the soil, he cultivates it nearly at hazard ; he can neither 
make any improvements in his modes of dressing the 
land, nor establish a good system of cropping ; he is 
obliged to forego the use of the best kinds of grasses, such 
as sainfoin and clover, because he cannot, in a short 
space of time, prepare the land for the reception of 
them ; neither can he hope to reap the benefit of the 
harvests, which they would, for a long time, produce. 
Thus, however intelligent a farmer may be, he is forced 
to live from day to day, and continue the imperfect 
system of cultivation commenced by his predecessors. 
He is obliged to obtain from the soil the utmost that it 
can furnish, in the state in which he takes it, without 
making any efforts to ameliorate the condition of the 
soil ; since at the end of his lease he would be liable 
either to have his rents raised in proportion to its in- 
creased productiveness, or to have his lease taken from 
him. 



iNtRODUCtlON. itXJCV 

Whilst the cultivation of artificial meadowSi, and the 
sound doctrine of a rotation of crops, were unknown, it 
was well to fix the duration of leases to three years ; 
then all agriculture consisted in two years of corn har- 
vests and one year of fallow ; the same course recoin^ 
menced every fourth year, and the successive farmers 
followed this plan without any deviation ; there was 
therefore no "inconvenience arising from supplying the 
place of one by another. But at this day it is well known^ 
that the establishment of artificial meadoWs, and a good 
system of successive crops, ought to form the basis of 
agricultural proceedings ; and it is acknowledged, that 
in order to execute these two great methods of amelio- 
ration, and to reap the fruits of them, a term of twelve 
or fourteen years is necessary ; the leases ought, there- 
fore, to be of at least that duration. In cases like this, 
the intereste of the proprietor and farmer are the same, 
nor can they be divided without injury to both. Ground 
well tilled increases in value, and thus enriches both the 
lessor and the lessee, whilst on those estates where the 
farmer sees himself secure of remaining for only three 
years, he cannot employ either his inteUigence or capital 
to advantage ; and he continues the imperfect course of 
management which he has hitherto pursued. 

Though agriculture has been gradually enriched by 
the introduction of many foreign plants, it still remains 
for us to adopt and naturalize others, and to extend the 
cultivation of those we now possess. The agriculture 
which is limited to the production of grain, supplies only 
a portion of the wants of society ; but if it includes in 
its labors all the productions of which the climate and 
soil will admit the cultivation, it will provide for the 



5LXXV1 INTRODUCTION. 

workshop of the artisan the materials of his industry, 
and thus supply every necessary of life. 

The lot of the agriculturist who cultivates only one 
species of produce, is always precarious ; he is dependent 
not only upon the chances of the harvest, but upon the 
rate of sales and the necessities of consumers ; whilst 
he who can procure from the soil a variety of produc- 
tions, is nearly sure of obtaining a market for some of 
them. It is thus at the south, where, independent of the 
productions common to all the country, the large propri- 
etor has still his harvests of wine, silk, and oil, and is 
indemnified by the abundance of one of these for the 
mediocrity of the others. 

Another advantage resulting to the agriculturist from 
the cultivation of a variety of productions, is the power 
of appropriating each portion of the land to the vegeta- 
ble for which it is best adapted, and, by this means, of 
preserving the soil in good condition. This mode of man- 
agement offers to the agriculturist immense resources for 
a rotation of crops ; where only grains are cultivated, it 
is impossible to establish a judicious succession of crops ; 
since it is only upon a variety of productions that there 
can be founded that system of rotation or succession, 
which will preserve the land in a constant state of fertil- 
ity, and permit it to produce without interruption. We 
have already introduced into agriculture the cultivation 
of grasses, grains, oil, and roots, and have thus furnished 
the materials for a succession of crops. We have for a 
long time raised flax, hemp, madder, and hops ; but we 
are still obliged to purchase of foreign nations the great- 
er part of those articles. Why cannot the soil of France 
furnish all we need of them ? Neither land nor hands 



INTRODUCTION. XXXVil 

are wanting to carry French agriculture to perfection ; 
the variety of the climate, the nature of the soil, the in- 
telHgence of the inhabitants, all permit the cultivation of 
nearly every thing which the wants of society require. 
In regard to position, France enjoys a privilege which 
no other nation can partake with her. 

I propose closing this work with two treatises; one 
upon the extraction of indigo from woad, and the other 
upon the manufacture of sugar from the beet root. 
These two branches of industry can yield to the agricul- 
tural interests of France an annual product of more than 
a hundred millions of francs. I shall submit to the airri- 
culturist the information which experience has afforded 
in regard to these new sources of prosperity ; and I do 
not doubt, if he will direct his attention to the subject, 
that he will appropriate a portion of the time included 
in his rotatiqn of crops, to the cultivation of two such 
important articles of importation. 

Whilst endeavouring to improve agriculture by applying 
to it the physical sciences, I have striven to avoid those 
stumblingblocks which would infallibly have turned me 
aside from the end which I proposed to myself to attain. 
I have endeavoured to keep in view, that I was writing 
for the agriculturist ; and that consequently my work 
ought to be clear, precise, and suited to his understand- 
ing, his education, and his means. In order to effect 
this, I have often borrowed his language, and I have 
nearly always relied upon his experience for the truth of 
the principles which I have advanced. Convinced that 
a process, the results of which have been proved, is 
at all times preferable to a purely theoretical statement, 
I have uniformly respected the knowledge acquired by 



XXXVlll INTRODUCTION. 

experience, and have proposed no new methods, except- 
ing those, the superiority of which over the old ones ap- 
peared to me to be fully confirmed. It is particularly 
important in agriculture to be cautious of innovations. 
There is not amongst husbandmen, generally speaking, 
a sufficient degree of know^ledge to enable them to ap- 
propriate the suitable soil and climate to foreign produc- 
tions; their best plan therefore is, to wait till some 
neighbour more enlightened than themselves can exhibit 
to them specimens of improvements ; which they may 
imitate without running much risk of ill success. 

1 shall perhaps be accused of having permitted myself 
to make some repetitions, and I candidly acknowledge 
that I have not endeavoured to avoid them. In a 
work like this, the subjects which are treated may often 
be presented under different forms; their phenomena 
always result from the same principles, but they may 
be most clearly elucidated by varying the modes of ex- 
plaining them. I have treated each subject in a manner 
entirely independent of the rest ; I have called to mind 
all the facts that could throw light upon it ; I have de- 
duced from them those principles which ought to direct 
the agriculturist in his labors ; and I have not feared to 
repeat a truth as often as I thought it could be done with 
advantage. 

This work is not perfect, and I can myself judge of 
its imperfections better than any one else ; but, such as 
it is, I believe it will be found useful. I trust that the 
application of the physical sciences to agriculture will 
be extended in proportion as those sciences advance ; 
and that a more thorough knowledge of the principles 



INTRODUCTION. XXXlX 

according to which they act, will occasion the rectifica- 
tion of any errors which may have arisen from their 
having been misapplied. The celebrated Davy, of Eng- 
land, has already published a work upon Agricultural 
Chymistry, from which I have borrowed many excel- 
lent principles : others will do better than we have 
done. 

Hitherto the physical sciences have been applied 
to the other arts much more than to agriculture ; 
many arts have, in our day, been originated or im- 
proved, by their means, whilst the progress made in ag- 
riculture has been very trifling. This difference ap- 
pears to me to proceed from two causes : the first of 
which is, that the greater part of the phenomena offered 
to us by agriculture are the effects of the laws of vitali- 
ty, which govern the functions of plants, and these laws 
are still unknown to us ; whilst, in the arts which are ex- 
ercised upon rude and inorganic matter, all is regulated, 
all is produced, by the action either of physical laws only, 
or of simple affinity, which are known to us. The 
second cause is, that in order to apply the physical 
sciences to agriculture, it is necessary to study their op- 
erations profoundly, not only in the closet, but in the 
fields. 

Though the proprietor of a large domain, of which I 
have for a time directed the labors, I feel that the facts 
which I have been able to collect upon various subjects, 
are still insufficient for the establishment of indisputable 
principles regarding them ; and in all such cases, I have 
done nothing but present to the reader the doubts or the 
simple probabilities which may have arisen firom my ob- 



Xi INTRODUCTION. 

servations. I may have committed many errors in my 
explanations, but I believe I have not misstated a single 
fact ; and it is in this belief that I offer this work to the 
agriculturist. 



CHYMIS 



APPLIED TO 



AGRICULTURE. 




CHAPTER I. 

GENERAL VIEWS OF THE ATMOSPHERE, CONSIDERED IN ITS 
EFFECTS UPON VEGETATION. 

In order to judge of the influence which the atmosphere 
exercises over vegetation, it is necessary to be acquainted 
with the peculiar and characteristic properties of each of 
the elements of which it is composed, and to study their 
action upon terrestrial bodies. 

The gases, azote and oxygen, are the two fluids, of 
which the atmosphere is essentially composed ; they are 
found in uniform proportions, even in the highest regions 
from which they have been brought. M. Gay-Lussac has 
established this fact, by a comparative analysis of the air 
taken from a height of twenty-three thousand feet, and of 
that which is upon the surface of the earth. 

There are certain other fluids, which are uniformly 
found in the atmosphere, but in very variable proportions ; 
the principal of these are carbonic acid, water, the elec- 
tric and magnetic fluids, light, and heat. The two last 
mentioned exercise a very marked influence, not only on 
vegetation, but on all the phenomena which terrestrial 
bodies present to our notice ; and though they do not 
enter essentially into the composition of the atmosphere, 
their action is so closely united with that of its principal 
constituents, as to be nearly inseparable from them. In 
order that the action of the atmosphere may be better 
understood, I propose to treat separately of all the fluids it 
contains, and afterwards to show the phenomena which 
the application of them to agriculture exhibits. 
1 



2 CHYMISTRY APPLIED TO AGRICULTURE. 

ARTICLE I. 

Of the Ponderable Fluids contained in the Atmosphere. 

The ponderable fluids contained in the atmosphere are 
azote, oxygen, carbonic acid, and water. 

1. Azote constitutes nearly four fifths of the atmospher- 
ic composition, and yet, by a singular caprice of nature, it 
exercises less influence on the substances of the three 
kingdoms, than any one of the other principles contained 
in the atmosphere. This gas is found in small quantities 
in some of the products of vegetables, and abundantly in 
those of animals. The presence of azote in some of the 
products of vegetation is to be accounted for by its pres- 
ence in the water, which plants imbibe from the atmo- 
sphere, and in those manures by which plants are nour- 
ished, and of which it forms one of the principal constitu- 
ents. 

In animals, in which azote is more abundant than in 
plants, the food by which they are nourished, and the air 
which is inhaled by respiration, concur equally to account 
for its presence. The experiments of Messrs. de Hum- 
boldt and Provencal upon fish ; Spallanzani upon reptiles ; 
and those of Messrs. Davy, Pfafl", Enderson, Edwards, 
Dulong, &.C. upon man, leave no doubt as to the absorp- 
tion of azote during respiration ; but this absorption is 
unequal and irregular, varying according to circumstances ; 
this gas differing from oxygen in this particular, at least 
in its effects upon animal and vegetable economy. The 
action of azote is, so far as it is known, of such trivial im- 
portance, that we are at a loss to account for the propor- 
tion which nature has assigned it in the composition of 
the atmosphere. It is supposed by some, that all the gas- 
es, all the vapors, and all the exhalations which arise from 
the surface of the earth, form in the atmosphere an im- 
mense magazine of azote, which is returned thence as it 
is needed, either for the support of animal and vegetable 
life, or to produce those phenomena of composition and 
decomposition, which are constantly renewing the surface 
of the globe. The specific gravity of pure azote is to 
that of the atmosphere in the proportion of 9,691 to 
10,000. 

2. Oxygen gas forms about one fifth of the atmosphere. 



CHYMISTRY APPLIED TO AGRICULTURE. 3 

The specific gravity of oxygen is to that of the atmo- 
sphere, as 11,036 to 10,000. The effects produced by ox- 
ygen are equally numerous and important; it supports 
animal life by respiration ; and combining with the carbon 
of the blood, it produces the greatest proportion of animal 
heat. The germination of seeds is promoted by this gas, 
and it is absorbed by the leaves of plants during the 
night : by its combination with the metals the oxides of 
them are formed. It is likewise the necessary agent of 
combustion, and concurs powerfully in the decomposition 
of all animal, vegetable, and mineral substances. 

In all cases where oxygen exerts its action, it combines 
with some one of the elements upon which it acts, forming 
acids with carbon, azote, sulphur, phosphorus, and many 
of the metals ; water with hydrogen, &c. The nature of 
the compositions, of which oxygen is an element, varies 
according to the proportions in which it enters into com- 
bination. 

When we survey the extent and importance of the ope- 
rations performed by this gas, and especially when we 
consider that it is constantly forming new bodies, with 
which it afterwards ceases to have any connexion, we are 
almost 1 .1 to fear, that the atmosphere mu-t be, sooner or 
later, exhausted of this active and regenerating principle ; 
but nature, we find, is continually repairing the loss thus 
sustained, by the production of equivalent quantities. The 
leaves of plants, under the influence of the solar rays, 
pour forth into the atmosphere torrents of oxygen, pro- 
duced by the decomposition of carbonic acid and of water; 
of which they appropriate to themselves the carbon and 
the hydrogen. 

It is without doubt possible, that in many situations the 
reproduction of oxygen is not in proportion to its con- 
sumption. This must happen especially where great quan- 
tities are required for respiration, or to support combus- 
tion. But this deficiency is only partial and momentary ; 
for the great mobility of the atmospheric fluid enables it, 
almost immediately, to restore its equilibrium from all 
points. The agitation of the winds mixes together, in 
proportions nearly constant, both the elements of which 
the atmosphere is composed, and the principal fluids 
which are found in it. 

The creation or destruction of any element is not to be 
found in the operations of nature. The numerous phe 



4 CHVMISTRY APPLIED TO AGRICULTURE. 

nomena of coraposition and decomposition, which take 
place upon the surface of the globe, present only changes 
of combinations, which are formed according to fixed, 
eternal, and unchangeable laws. Thus nature is regene- 
rated, without being impoverished ; and matter expe- 
riences only those changes which are reproduced uniformly 
and periodically, especially in organic bodies. 

3. Carbonic acid is found constantly, but in various 
proportions, in the atmosphere. Though much heavier 
than azote or oxygen, its weight being to that of the 
latter, as 1,520 to 1,000, it is found disseminated through- 
out the whole atmospheric region. The elder M. de 
Saussure has, by means of lime-water, drawn it from the 
air upon the summit of Mont Blanc. From the results of 
all the experiments that have been made, there can be no 
doubt, that the proportions of azote and oxygen in the 
composition of the atmosphere are uniform and nearly in- 
variable ; and it appears to be likewise proved, that car- 
bonic acid is also found there, and at all heights, but in 
various proportions. 

M. Th. de Saussure has compared the different portions 
of carbonic acid in the atmosphere which he has analyzed, 
and found the difference between them, in summer and in 
winter, to be as follows. 

IN WINTER. 

31st of January, 1809, 10,000 parts of air 

contained carbonic acid 4,570 

2d of February, 1811 " " 4,660 

7thof January, 1812 " " 5,140 

The mean term in winter from 10,000 parts of air was, 

In volume . . . 4,790 

In weight . . . 7,280 

IN SUMMER. 

20th of August, 1810, 10,000 parts of air 

contained carbonic acid 7,790 

27thof July, 1811 " " 6,470 

15thof July, 1815 '' " 7,130 

The mean term in summer from 10,000 parts of air was, 

In volume . . . 7,130 

In weight . . . 10,830 
Without doubt, when the air is tranquil, or when the 
carbonic acid, which is produced so abundantly by fer- 
mentation, respiration, combustion, &-c., is retained in 
confined places, the quantity of this acid will exceed the 



chymistry applied to agriculture. 6 

ordinary proportion ; but from the moment that the agita- 
tion of the winds can mingle it with the atmosphere, it 
is spread and diffused towards all points, according to cer- 
tain fixed laws. Unless in some extraordinary cases, 
which form exceptions to the general rule, carbonic acid 
exists in the atmosphere at most only in the proportion of 

Carbonic acid is constantly absorbed and decomposed 
by the leaves of plants. The carbon is appropriated by 
the plants to their own support, and the oxygen is thrown 
out into the atmosphere. Carbonic acid combines with 
the lime in fresh mortar, and causes it to return to its 
original state of lime-stone. Under the pressure of the 
atmosphere, water will hold in solution nearly its own 
volume of carbonic acid, and be slightly acidulated by it ; 
but under the force of a greater pressure, it will contain 
a much greater quantity. Water, thus charged, froths 
like Champagne wine, which owes its effervescence to the 
carbonic acid produced by the fermentation of the wine 
in well-corked bottles. In some recent experiments car- 
bonic acid gas has been reduced by compression to a 
liquid state. 

4. Water exists in the atmosphere, under the form of an 
elastic fluid. When it is absorbed by bodies for which it 
has a strong affinity, such as the calcined muriate of lime, 
the portion of air from which it is taken, is diminished in 
weight and volume. This has been proved by the experi- 
ments of the elder M. de Saussure and of Davy. The 
quantity of aqueous fluid contained in the air, varies ac- 
cording to the temperature of the atmosphere, and in- 
creases in proportion as that is elevated. At 50^ Fahren- 
heit it forms in volume nearly -J^ of the atmospheric fluid; 
and as its density is to that of the atmosphere in the pro- 
portion of 10 to 15, it constitutes nearly j^ of its weight 
(Davy). 

The aqueous fluid forms, when the atmospheric tempe- 
rature is 34° Centigrade z= 93°.20, (Davy says at 100°,) 
-y\ of the volume of the air, ard ^\ of its weight. 

The elder M. de Saussure, in his beautiful Treatise 
upon the Hygrometer^ has determined the weight of the 
water contained in a cubic foot of air, at different tempe- 
ratures, and has prepared the following table of the 
results. 

1* 



6 



CIIYMISTRY APPLIED TO AGRICULTURE. 



Degrees of the 
hygrometer. 


Weight 
of tlie water contained in 
a cubic foot of air at 
66°.2 Fahrenheit. 


Weight 
of the water contained in 
a cubic foot of air at 
45''.9 Fahrenheit. 


f 


Grains. 


Grains. 


< 10 


0.4592 


0.2545 


20 


1.0926 


0.6349 


30 


1.7940 


1.0833 


40 


2.5634 


1.5317 


50 


3.4852 


2.0947 


60 


4.6534 


2.7159 


70 


6.3651 


3.3731 


80 


8.0450 


4.0733 


90 


9.7250 


4.9198 


98 


11.0690 


5.6549 



" Consequently," adds M. de Saussure, ^' I do not think 
we are far from the truth, in assigning 11 grains of water 
to saturate a cubic foot of air, at the temperature of 15** 
of Reaumur," (i=:65°.75 Fahrenheit.) ''The solution of 
these 11 grains of water in a cubic foot of air at the tem- 
perature of 15° Reaum. (= 65°. 75 F.) increased the den- 
sity of the air so much, that the barometer, which before 
was at 27 in., rose to 27 in. 5 ''"^'79,411, that is to say, 
about 27 in. 6 lines ; consequently, the density of the air, 
or its volume in the receiver, was increased about J^." 

When the temperature of the air is diminished, the 
aqueous fluid is condensed, and appears in the atmosphere 
in the form of vapor, and is deposited in the state of dew. 
The moisture of the night air from this cause, during the 
heat of summer, restores vegetation from that state of Ian- 
guor produced by the too great warmth of the day. 

Oxygen and azote have been classed among the simple 
bodies ; carbonic acid and the aqueous fluid among the 
compound bodies, of which the principal constituents are 
known, and which can be formed and decomposed at will. 

. carbon 27.36 
. oxygen 72.64 
. hydrogen 11.06 
. . . oxygen 88.94 

Oxygen and azote constitute, essentially, the atmo- 
sphere ; since, when the two other principles are separated 
from it, it still retains nearly all its characters of form, 



100 parts of carbonic acid contain ; 
100 parts of water contain 



CHYMISTRY APPLIED TO AGRICULTURE. 7 

elasticity, dz.c. It however loses its most important powers 
of influencing vegetation ; so that all the substances found 
in the atmosphere are necessary to the production and re- 
newal of the phenomena which the three kingdoms pre- 
sent to us. 

Of the four principles of which I have just spoken, as 
constituting the atmosphere, the aqueous fluid is that 
which appears to be the least closely united to the others ; 
since a change of temperature alone is sufficient to pro- 
duce a change of its proportions; whilst azote, oxygen, and 
carbonic acid preserve, always, nearly the same relative 
proportions ,• nor can they be varied, or disunited, by 
means of compression or change of temperature. The 
aqueous fluid does not rise to a great height in the atmo- 
sphere ; for, according to the reports of those experimental- 
ists who have arrived at their conclusions by the assis- 
tance of air-balloons, the higher regions of the atmo- 
sphere are very dry, so as to produce, by the avidity with 
which they absorb the moisture from the boat of the bal- 
loon, a warping and cracking of its boards, as if they had 
been exposed to a strong heat. This effect is produced 
by the dryness of the atmosphere and the diminution of 
its specific gravity. 

The manner in which the atmospheric elements are 
united is worthy of notice. This union is sufficiently 
strong to counterbalance the difference in their specific 
gravities, and not to allow them to be separated by com- 
pression, or the tumultuous agitation of the air; and yet 
it permits the various principles to be decomposed and 
isolated, by presenting to them bodies for which they have 
some slight affinity. Thus, if we inclose under a bell- 
glass any volume whatever of atmospheric air, the aqueous 
fluid may be extracted from it, by the calcined muriate of 
lime. The combustion of phosphorus in it will absorb 
the oxygen gas; lime-water, or the caustic alkalies, will 
combine with the carbonic acid ; and nothing will remain 
but azote, which is the portion that has the least tendency 
to form combinations. 

This weak state of union among the principles con- 
tained in the atmosphere is necessary, in order that they 
may exert their powerful and constant action upon all the 
various bodies which cover the surface of the globe ; 
the composition and decomposition of which cannot be 
effected otherwise than by the means of these agents. 



8 CHYMISTRY APPLIED TO AGRICULTURE. 

Independently of those bodies which essentially consti- 
tute the atmosphere, there are mingled in it the exhala- 
tions constantly arising from the earth ; these are again 
disengaged from the air, and precipitated, as soon as the 
heat, or any other cause which occasioned their ascen- 
sion, ceases to act upon them. These exhalations modify 
the properties of the air, and affect its purity. The oxy- 
gen and the water of the atmosphere become impregnated 
v/ith the particles of the exhalations which are deposited 
with them upon the surfaces of other bodies, where they 
remain in contact, or enter into combination, with them. 
The origin and dissemination of many maladies may be 
traced to this source ; the germ of them is carried 
through the air by the aqueous fluid. And for the same 
reason it is, that intermittent fevers are endemic in those 
situations, where large quantities of animal or vegetable 
matter are undergoing decomposition, as upon the borders 
of ponds and marshes ; and that the miasm, which arises 
from numerous animal remains in a state of decompo- 
sition, becomes a fruitful source of disease. It is for the 
same reason also dangerous, under some circumstances, 
to breathe the evening air ; the aqueous fluid contained in 
it is loaded with the noxious principles, which the heat 
of the sun during the day had caused to ascend into the 
atmosphere. The disagreeable odor, conveyed to us in 
mists, is owing to the power of the aqueous fluid in trans- 
mittingr the exhalations arisincr from the earth. 

mi • . 

The manner in which the air conveys to us the per- 
fume of plants, and the odor which it contracts from the 
exhalations of bodies in a state of decomposition, indicate 
clearly its influence in producing maladies, and still more 
plainly its power of propagating those that are contagious. 



ARTICLE II. 

Of the Imponderable Fluids contained in the Atmosphere, 

Besides the ponderable substances which constitute the 
atmosphere, and those which are found in it accidentally, 
it receives some imponderable fluids, of which the effects 
are less known, but which appear to play an important 
part in the atmospheric phenomena; of this number is 
the electric fluid. 



CHYMISTRY APPLIED TO AGRICULTURE. 9 

1. Electricity is developed by friction, and transmitted 
by simple contact. It is accumulated in bodies when they 
are insulated ; and it is communicated in the same man- 
ner as heat, when bodies which are non-electric ap- 
proach those which are electric. 

The singular properties of the electric fluid contained 
in the atmosphere, and the frequent variations which it 
undergoes, give rise to numerous phenomena, for which 
observation and experiment enable us to account. When 
this fluid is abundantly diff'used throughout the atmo- 
sphere, it exercises a powerful influence over vegetation, 
excites the action of oxygen, and determines the conden- 
sation of the aqueous fluid. Davy has observed that grain 
germinates more quickly in water charged with positive 
electricity, than in that which contains the opposite prin- 
ciple ; and that it is a well known fact, that fermentation 
takes place most rapidly during a thunder-storm, and 
that a liquid, composed of a variety of principles not very 
closely united, milk for instance, is decomposed, and be- 
comes acid under a highly electric state of the air. 

2. Whatever may be the opinion we may adopt, as to 
the nature of the principle of heat, there can be no doubt 
that there exists in the atmosphere, and in all terrestrial 
bodies, an imponderable fluid, unequally imparted to them, 
and which renders their state solid, liquid, or gaseous, 
according as the afiinity, existing between their par- 
ticles and the fluid of heat, is more or less strong. It is 
this state which we regard as the natural state of bodies. 

Exposed to an equal degree of atmospheric tempera- 
ture, all bodies, in their natural state, are penetrated by 
unequal quantities of the fluid of heat ; but as the fluid is 
in combination with the particles of the bodies, and thus 
forms one of their constituent principles, it does not de- 
velope its most important property, which is that of heat ; 
and in this state it has been agreed to call it caloric, and 
it only takes the name of heat when it is free, and disen- 
gaged from all combination. 

Caloric, interposed between the molecules of bodies, 
tends to separate them from each other ; and when accu- 
mulated beyond its natural quantity, the excess acts as 
heat ; changing the form of bodies, and causing them to 
pass from the solid to the liquid state, or from the last to 
that of vapor. 

Those bodies which exist naturally in a gaseous state, 



10 CHYMISTRY APPLIED TO AGRICULTURE. 

and which are rendered solid by being brought into com- 
bination with other substances, return to their natural 
state as soon as a sufficient degree of heat is applied to 
destroy the force of the affinity which unites them to their 
base. But those which are not originally gaseous in their 
form, under the influence of heat pass through all the 
degrees intermediate between their natural state and that 
of imperceptible vapor ; and return to the concrete state 
when deprived of the excess of heat which had been ap- 
plied to them. 

Caloric can be extracted from bodies by percussion or 
compression, in the same manner as water is expressed 
from a substance which has imbibed it. When a body is 
deprived of its caloric by either of these means, the mole- 
cules composing it are brought closer to each other, and 
its porosity, and consequently its volume, diminished. 
The act of striking or rubbing hard bodies together, 
produces the same effiect ; the portion of caloric, which is 
in either case set free, acts as heat. 

The temperature of bodies can be lowered, or elevated, 
by placing them in contact with other bodies more or less 
hot than themselves. The fluid of heat will pass from 
one to the other, and produce an equilibrium in their 
Btate, according to their respective capacities for caloric, 
which enable them to absorb unequal quantities of it. 

All bodies in their natural state contain a determinate 
portion of caloric ; but when their density undergoes a 
change, by the variations of temperature to which they 
are exposed, they lose or absorb caloric, in proportion to 
their contraction or dilation. The gases, which become 
solid by entering into combinations, the vapors which are 
condensed, the solids which are contracted, impart to the 
air a portion of their caloric, which becomes heat ; whilst 
all these bodies, on receiving heat from the air, are 
dilated. 

The phenomena of composition and decomposition, 
which uninterruptedly renew the surface of our globe, 
give rise every moment to the emission or absorption of 
caloric. Two substances, entering into combination, form 
a compound which perhaps requires more or less caloric 
than is contained in the two component principles ; and 
then either heat or cold is necessarily produced during 
the operation. Those gases, which become solid by en- 
tering into combination, part with their caloric whilst un- 



CHYMISTRY APPLIED TO AGRICULTURE. 11 

dergoing the change, and thus produce heat. In combus- 
tion, where oxygen is the principal agent, there is a 
constant disengagement of caloric, because that gas, in 
general, forms solid or liquid compounds with combustible 
substances ; and it gives out a portion of the caloric which 
preserve,fl it in its gaseous state. 

These principles established, we can easily explain a 
part of the effects produced upon vegetation by the varia- 
tions of temperature. 

The changes of temperature, experienced by the atmo- 
sphere in the course of a year, are so great, as to cause 
some liquids to pass alternately either to the solid or aeri- 
form state, and some solid bodies to become liquid. The 
natural effect of heat upon these bodies is, by dilating 
them, to weaken the force of cohesion which unites their 
molecules, and, by facilitating the action of chymical 
affinity, to enable them to enter into combination with 
foreign bodies. Thus heat renders the juices of plants 
more fluid, and facilitates their circulation through the 
cells and capillary vessels ; and, by giving activity to the 
suckers of roots, enables them to draw from the earth the 
juices necessary for their nourishment. 

Above a certain temperature, heat, by promoting evapo- 
ration, causes the juices of plants to become thickened 
and dried in their organs, and thus vegetation is arrested, 
and life suspended. This effect always takes place during 
great heats, when neither rain, dew, nor irrigation can 
sufficiently repair the loss occasioned by evaporation. 
This effect would be more frequent, if provident Na- 
ture did not employ means to moderate the action of heat. 

The first of these means is the transpiration of the vege- 
tables themselves, which cannot take place without carry- 
ing off a large portion of heat, and thus preserving the 
transpiring body at a temperature below that of the air. 
The second means is found in the organization of leaves, 
which are the only parts of a plant where transpiration 
takes place. That surface of leaves which is exposed to 
the direct rays of the sun is covered by a thick epidermis, 
which resists the calorific rays. In herbaceous plants, as 
in the stalks of grasses, this covering is composed princi- 
pally of silex. In other plants it is analogous to resin, 
wax, gum, or honey ; whilst the epidermis, which covers 
the opposite sides of the leaves, is fine and transparent. 



12 CHYMISTRir APPLIED TO AGRICULTURE. 

It is by this, that transpiration and the absorption of 
nourishment from the atmosphere are carried on. If we 
should reverse the order of things, and present the under 
surface of a leaf to the rays of the sun, we should very 
sOon see that it would make great efforts to resume its 
natural position. 

When a plant is dead, or rather when an annual plant 
has fulfilled its destiny, giving assurance of its reproduc- 
tion by the formation of its fruit, the action of heat and of 
the other chymical agents is no longer modified by any of 
the causes of which I have just spoken, and the plant re- 
ceives their impression in an absolute and unmodified 
manner. When the temperature of the atmosphere sinks 
below a certain point, the fluids in plants become con- 
densed, the movement of the juices is retarded, the 
activity of their organs languishes, and is at length sus- 
pended, until restored by the return of heat. The action 
of the atmosphere upon plants, when deprived of its due 
proportion of heat, is however modified by the emission 
or disengagement of caloric, which is always given out 
when liquids are condensed, or solids contracted ; and 
this occasions the temperature of plants, during the winter, 
to be always a little higher than that of the atmosphere. 

It sometimes happens that the temperature of the at- 
mosphere sinks so low, as to produce fatal effects upon 
plants by freezing their sap, and thus occasioning their 
death. This effect does not always depend upon the in- 
tensity or degree of cold to which they are exposed, but 
upon particular circumstances. I have seen olive trees 
resist a temperature of 22°.2 Fahrenheit, and perish from 
that of 28°. 6, because in the last case the snow, which 
had collected upon the branches of the trees during a 
night, was dissolved the following day by the heat of the 
sun, and the wet tree was exposed during the succeeding 
night to the action of 28°. 6. There is nothing more dan- 
gerous for corn and grasses, than those frosts which follow 
immediately after a thaw, because the still wet plants, not 
being deeply rooted in the ground pulverized by the frost, 
have no means of defending themselves from the effects of 
the cold. 

3. Sennebier was the first to admit that the influence of 
light was hurtful to the germination of seeds. Ingen- 
houz confirmed this opinion by actual experiment ; but 
M. de Saussure, who caused grains to germinate under 



CttYMlSTRY APPLIED TO AGRICULTURE. 13 

two receivers, the one opaque, and the other transparent, 
is convinced that germination took place in both cases at 
the same time ; but that the subsequent vegetation w^s 
more rapid and vigorous under the transparent, than 
under the opaque receiver. It is easy to reconcile these 
opinions and resuhs, though apparently so contradictory, 
by separating the action of heat from that of light. As 
plants transpire very little during their first stage of ger- 
mination, if they are exposed to the united influence of 
the two fluids, that of heat will exercise upon them its 
full force, because there is no evaporation from them to 
temper its effects, and their delicate organs will be with- 
ered and dried up. It is for this reason that gardeners 
are so careful to shelter their nurseries from the rays of 
the sun, and not to expose their plants, till by the devel- 
opement of their leaves they are able to moderate the 
effects of heat by transpiration. 

Though the action of light upon vegetation does not 
appear to be so important as that of the other fluids of 
which I have spoken, it is not in reality less so. Plants, 
which are raised in the shade or in darkness, are nearly 
or quite without color, perfume, taste, or the firmness of 
texture of those, that are exposed to the direct rays of the 
sun ; and if the luminous fluid does not combine with the 
organs of plants, we cannot deny that it is a powerful 
auxiliary in their combinations. 

It is generally acknowledged that plants do not emit 
oxygen gas, excepting when exposed to the direct rays of 
the sun ; and it is known also that flowers rarely produce 
fruit, if raised entirely in the shade. According to the 
observations of M. Decandolle, the sensitive plant, if car- 
ried into the shade, closes its leaves as during the night, 
and reopens them immediately upon being again exposed 
to the rays of the sun or of a lamp. 

The grand discoveries of Herschel have thrown great 
light upon these delicate questions. That learned philoso- 
pher has proved, that amongst the various rays consti- 
tuting a pencil of light, there are some that possess nearly 
exclusively the property of being luminous, others, that of 
affording heat. Wollaston and Ritter have added to these 
important facts, that there exists a third species of rays, 
which appear to act upon bodies as powerful chymical 
agents. 

When we reflect upon the influence which the atmo- 
2 



14 CHYMISTRY APPLIED TO AGRICULTURE. 

Sphere exercises over vegetation and over the principal 
operations which are carried on in rural establishments, 
such as fermentations, the preparation of various produc- 
tions, and the decomposition of some substances, in order 
to apply them to particular purposes ; we are astonished 
at finding nowhere any of the simple and unexpensive in- 
struments which announce its changes every moment. 

I do not propose that delicate or complicated instru- 
ments should be provided ; but I wish to find on every 
farm an hygrometer, to ascertain the humidity of the at- 
mosphere, a thermometer to indicate the changes of tem- 
perature, and a barometer to determine the weight of the 
atmosphere. This last instrument would be particularly 
valuable, as predicting the changes of the weather; the 
rising of the mercury announces the return of dry weather, 
and its sinking warns us of rain and storms. We can 
regard these variations but as signs ; but they are signs 
much more certain than those which country people de- 
rive from the changes of the moon. 



CHAPTER II. 



OF THE NATURE OF EARTHS, AND THEIR ACTION UPON 
VEGETATION. 

Nearly all vegetables derive their support from the 
earth. There are however some, the seeds of which, be- 
ing deposited upon trees by birds or by the winds, germi- 
nate and grow, appearing to be in the situation designed 
for them by nature ; such are the mistletoe, the mosses, 
&LC. There are others that float upon the water, or fasten 
themselves upon dry rocks, upon slates, or tiles ; of the 
last kind are the fleshy plants. As the earth furnishes 
the greatest number of plants, and all those which are of 
the most importance to man, its influence upon vegetation 
19 of the greatest consequence, and at the same time one 
of the most difficult things of which we can treat. 

Plants are not, like animals, endowed with powers of lo- 
comotion ; but are always fixed to a limited portion of the 
soil. They depend upon the small space which they oc- 
cupy for the supply of their wants ; they can place under 
contribution only those portions of the surrounding air, 



OF MOULD. 15 

earth, and water that come in contact with them ; it is 
necessary, then, that they should find immediately around 
them the nutritive principles requisite for their growth, 
and for the exercise of their functions ; it is necessary 
that they should be able to extend their roots, in order to 
draw from the soil its nourishing juices; and to fasten 
themselves in the earth, so as to be secure from being 
dried up by heat or uprooted by the winds. 

As all the qualities required by a vigorous vegetation 
cannot always be found united in land appropriated to cul- 
tivation, we are led to examine the nature of earths, and 
the differences which exist among them. 



ARTICLE I. 

Of Mould. 



All plants, when dead, are more or less readily decom- 
posed ; and in undergoing these changes, which are 
greatly facilitated by air and heat, they form products 
with which it is of importance for us to be acquainted ; 
as the principal aliments of living plants are furnished by 
those that are dead. Decomposition is most rapid in suc- 
culent vegetables, and in those which are collected in 
heaps ; but a high degree of atmospheric temperature and 
the humidity of plants contribute powerfully to accelerate 
it. During decomposition much carbonic acid is given 
out ; a part of this exists in combination with the constitu- 
ent principles of the plant, and a part of it is produced by 
the action of the oxygen of the atmosphere upon the car- 
bon of the plant; hydrogen, which is probably furnished 
by the decomposition of the watery particles, and is 
generally carburetted, is likewise exhaled, as also am- 
moniacal gas when its elements exist in the plant. 
When large masses of vegetables are in a state of fermen- 
tation, heat is always produced ; but if they have been 
dried, it is necessary to collect them into heaps, and 
moisten them slightly in order to determine their fermenta- 
tion and decomposition ; in this case the heat produced 
is sometimes so great as to cause the combustion of the 
mass ; a phenomenon which occurs when hay is stacked 
without being sufficiently dry, or when ropes, hemp, or flax 
are piled up wet. 



16 CHYMISTRY APPLIED TO AGRICULTURE. 

When all the parts of a plant are decomposed, there is 
produced an earthy residunrn of a brown color, which is 
called mould. In this, besides the salts and the earths 
which it contains, are found some oils and extractive 
principles which escape decomposition. 

The distillation of mould in a retort, produces much 
carburetted hydrogen, some carbonic acid, a bituminous 
empyreumatic oil, and some water holding in solution 
pyroligneous acid and carbonate of ammonia. 
- The analyses by fire do not produce any substances, 
such as exist in vegetables and animals; they decompose 
the natural products of the plant, and present their ele- 
ments under different combinations. The analysis of 
mould by washing in water, leads us to a better knowledge 
of its component parts, and of its actions upon vegetation. 
M. de Saussure found, that pure mould, formed in an open 
field, leached twelve times with boiling water, yielded a 
dry extract equal to yV of its weight; rich garden soil, 
and the light soft earth from a field which bore a good 
crop, yielded the same extract, but in less quantity. This 
learned philosopher is convinced, that the excellence of 
mould does not depend upon the proportion of the ex- 
tractive matter which it contains. 

Mould furnishes by distillation nearly the same princi- 
ples after being deprived of its extract by washing, as 
before ; but its powers of supporting vegetation are less in 
the first case, than in the second. 

When, after repeated washings, no more extract can be 
obtained from mould, it is only necessary to moisten it, 
and leave it exposed to the air for three months, in order to 
have it yield fresh supplies. These macerations, continued 
for a long time upon the same mould, have always produced 
colored infusions, approaching in their qualities to the 
extract, (Saussure,) which proves that new combinations 
are formed by the successive changes of vegetable pro- 
ducts, and that the result of these combinations is soluble 
in water, after it appears to have exhausted its solvent 
power upon the bodies. This fact is the more important, 
as it shows that the nutritive quality of vegetable manures 
may continue during the whole time of their decomposi- 
tion, because they form new products soluble in water, 
which will afterwards serve as nourishment for plants. 
This fact proves still fiirther, that some substances, 
by their nature insoluble in water, may form excellent 



OP MOtfLD. 17 

manures during the various stages of their decomposition, 
by giving rise to the formation of products very soluble. 

M. de Saussure found, that mould which had been de- 
prived of its extract, contained a little more carbon, than 
that which had not been so deprived ; the former yielded 
33i, the latter 31. 

One hundred parts of the dry extract of turf mould 
furnished 14 parts of ashes, which, when leached with 
boiling water, afford ^g^^y = ^ly of salts composed of pure 
potash, muriates, and alkaline sulphates. 

It is necessary to observe, that when mould is reduced 
to ashes, the action which water exercises upon it is in 
inverse proportion to the power of the heat to which it 
has been subjected ; if that have been very intense, a sort 
of semi-vitrification takes place, which unites the earthy 
principles with the alkaline salts, and renders the mass 
less soluble in water. M. de Saussure has proved, that 
boiling water cannot extract at most more than y§^ =z -^ 
of the salts contained in the ashes of mould ; whilst after 
having obtained ^V "^ alkaline salts from the dry extract 
of mould, by the aid of boiling water, he procured by 
another analytical process, a quantity of salts equal to the 
first. 

With the exception of the earthy and saline principles 
contained in mould, in the proportion of 5 to 7, all the 
other principles are entirely destructible by the action of 
air and water. 

When mould is exposed to the action of air, or entirely 
immersed in water, it suffers no decomposition ; but when 
it is brought into contact with the atmosphere, or with 
oxygen gas, after having imbibed water, the oxygen com- 
bines with the carbon of the mould, and produces a vol- 
ume of carbonic acid gas, always equal in volume to the 
quantity of water imbibed ; when this water is sufficiently 
impregnated with carbonic acid, the volume of air en- 
closed under a bell glass, in contact with the mould, 
suffers no further change. 

The carbon of which the mould is deprived by its union 
with oxygen, is not in proportion to the loss occasioned 
by decomposition ; it still disengages carburetted hydro- 
gen and water, which proves the combination of oxygen 
with hydrogen, and of the last with carbon. The decom- 
position of mould is very slow, and even when aided bv 
2* 



18 CHYMISTRY APPLIED TO AGRICULTURE. 

the concurrence of air, heat, and water, is completed only 
at the end of some years. 

Land owes its fertility mostly, if not wholly, to the 
presence, in a greater or less abundance, of principles 
analogous to those constituting mould. These principles 
are furnished by manures, and by the decomposition of 
plants ; but each harvest causes a diminution of them, a 
part being washed away by rains, and a part absorbed by 
the crops which are raised ; thus the soil is deprived by 
degrees of its nutritive qualities, till at length nothing re- 
mains but an earthy residuum, deprived of its nourishing 
juices, and completely barren ; it is to restore its fertility 
that land must be manured afresh, after having yielded 
several crops. 



ARTICLE IL 

Of the Nature of Soils. 

The question which we are now about to treat, is one 
of the most difficult in agriculture, but as it is perhaps 
one of the most important, we ought to give it the greatest 
attention, and to direct all our researches to proving the 
difference existing amongst arable lands, and their various 
properties. 

The earth furnishes support to nearly all plants ; and 
as each species of these requires a soil suited to its par- 
ticular organs, we find that different portions of the earth 
differ widely amongst themselves in character. An ac- 
quaintance with the nature of soils is especially necessary, 
as it serves to throw light upon the cultivation of vegeta- 
bles, which are principally nourished by them, and upon 
the suitable adaptation of which most of their properties 
depend. 

Arable soils, which are the only ones of which I shall 
here speak, are generally composed of silica, lime, alumi- 
na, magnesia, oxide of iron, and some saline substances. 
The various characters of soils arise from the different 
proportions in which their component parts are combined; 
and the name given to each is according to that of the pre- 
dominating portion of earth found in it, as siliceous, cal- 
careous, argillaceous, 6lc. It is necessary that they should 



FORMATION OF ARABLE LANDS. 19 

be classed according to their nature, that the degree of 
fertility of each, and the kind of cultivation to which it is 
best suited, may be known. 

Not one of these earths is by itself well adapted to cul- 
tivation, but by their mixture they correct the qualities, or 
supply the deficiencies of each other ; the best soil is that 
which unites the greatest number of the properties most 
suited to vegetation. 

There are few soils that do not contain, in addition to 
the abovementioned earthy and saline principles, some 
portion of substances, resulting from the decomposition of 
animal and vegetable matter, by which, other circum- 
stances being the same, their fertility is very considerably 
influenced. 



ARTICLE III. 

Of the Formation of Arable Lands. 

Arable lands are almost entirely produced by the de* 
composition, from various causes, of the rocks which form 
the basis of our globe. The water, which flows in tor- 
rents from the tops of the mountains, abrades their sides, 
and detaches from them large portions of rock, which 
being afterward swept by the force of the current, and 
constantly dashed and rubbed together, have at length 
their corners and edges broken off", their forms rounded, 
their surfaces smoothed, and their size diminished, till 
they form, successively, pebbles, gravel, sand, and mineral 
slime. 

The number and magnitude of the stones found in the 
beds thus deposited, depend upon their distance from the 
mountains whence they have been brought, upon the 
harder or sofl;er character of the rock whence they have 
been broken, and upon the force of the currents by which 
they have been acted upon. 

Nearly all the lands of our rich valleys owe their origin 
to the decomposition of rocks, and we can judge of the 
nature of the principles which compose them, by knowing 
those of the mountains whence they have been brought. 
The deposits from granitic mountains, consisting of quartz, 
feldspar, and mica, form soils mixed with silica, alumina, 



20 CHYMISTRY APPLIED TO AGRICULTURE. 

lime, magnesia, and oxide of iron. Those from moun- 
tains of the quartzeous formation are composed, ahnost 
entirely, of siliceous earth, and give rise to soils of an 
analogous character ; and so on of the rest. 

It would, however, be erroneous to suppose that the 
lands formed by the waste of mountains are throughout 
of the same nature, or contain the same principles, in the 
same proportions, as the rocks from which they have been 
produced. Upon this supposition it would be necessary 
that all the substances, originally contained in any one 
kind of rock, should be of equal specific gravity, and pos- 
sess an equal affinity for water; and this is not the case. 
Those, the particles of which are held in the closest 
union, are deposited first, whilst the others are carried on 
by the current ; silica, and the oxides of iron, predominate 
in those which are first deposited ; then lime, alumina, and 
magnesia. 

It is very interesting to trace the changes which take 
place in alluvial soils, according to their distance from the 
rivers which brought them ; whether we consider, in these 
changes, the division and mixture of the constituent prin- 
ciples, or the varieties which they present at different dis- 
tances from the sources of their origin. 

Independently of the various degrees of specific gravity 
and hardness which exist amongst the earthy principles, 
there are other causes which contribute powerfully to affect 
the nature of alluvial lands. Rivers receive, in their 
courses, many tributary streams, which, mingling the frag- 
ments that they carry with the spoils of the others^ 
modify to an illimitable extent the soils which they pro- 
duce, It frequently happens, that this mixture of the mud 
of two rivers, produces a soil more fertile, than would 
have been formed by either of them singly ; the qualities 
of one servincf to correct the deficiencies of the other. 
Thus the washings from moutnains of the quartzeous form- 
ation, combined with the argillaceous and calcareous por- 
tions of the wrecks of other mountains, constitute a more 
productive soil than would be furnished by either sepa- 
rately. 

The greatest part of those lands now appropriated to 
the richest culture, are but the ruins of those imposing 
mountains, the sides of which, rent away and carried off 
by torrents, are in their passage reduced to dust, and de- 
posited in the valleys to form the basis for agriculture. 



FORMATION OF ARABLE LANDS. 21 

It is not possible to refer to any other causes than those 
I have just pointed out, the formation of the arable lands 
of the valleys; those which are found upon the vast table 
lands, which crown the tops of mountains or extend along 
their sides, must have had some other origin. The con- 
stant action of air and water, alone, might have produced 
the plains, but so gradually, that their effects would only 
be perceptible after a lapse of many ages, if other agents 
did not conspire with them to hasten the decomposition of 
the rocks, and to convert them into arable land. 

The decomposition of such rocks, as are by their want 
of density permeable by water, must be much more rapid 
than that of those, in which the particles are more closely 
united ; and rocks, of which the constituent principles pos- 
sess some affinity for air and water, will yield much more 
readily to their action, than those in which no such affinity 
exists. 

In order to account for the action of air and water, upon 
rocks, it is necessary to consider, that many among them 
contain lime, very imperfectly saturated, and usually some 
oxide of iron, at its lowest state of oxidation ; the lime is 
constantly disposed to imbibe from the atmosphere its car- 
bonic acid, whilst the oxide of iron combines with its oxy- 
gen ; these combinations will be very rapid, if neither the 
lime nor the oxide of iron is united to any other sub- 
stances, which, not possessing the same affinities for the 
constituents of the atmosphere, oppose its action upon 
them. 

Rocks are frequently moistened by water for a consid- 
erable length of time, without being much affected by it ; 
but when it has at length insinuated itself into their pores, 
and become there converted into ice by the cold, it de- 
stroys by its expansion the cohesion of their particles, pro- 
ducing rents and fissures, and thus giving access to the 
air, which combines with the lime and oxide of iron, and 
produces an immediate change in all the surfaces exposed 
to its action ; from this moment the process of decompo- 
sition goes on more rapidly than before. The lichens and 
mosses, which fasten themselves upon the surfaces of rocks, 
continue and increase the change ; their delicate roots are 
constantly enlarging the crevices caused by the water, by 
the effort they make to insinuate themselves into them ; 
and by their decay they afford light successive layers of 
pulverized vegetable matter. 



22 CHYMISTRY APPLIED TO AGRICULTURE. 

Water, by its own action, will penetrate by degrees into 
the earthy principles of rocks, and produce, at length, the 
effect mentioned above ; but its power is wonderfully in- 
creased, whilst passing from its liquid state, to that of ice. 

As soon as the surface of a rock is furrowed, and the 
mosses and lichens have fastened themselves upon it, all 
the plants which require but little nourishment, take root 
and decay there in turn ; and the product of each succes- 
sive decomposition adds something to the slight bed of 
earth formed by the first, till in time a soil is produced, 
fit for cultivation. 

Hitherto we have considered only those circumstances 
which explain to us the formation of arable lands ; these 
causes have, without doubt, placed at our disposal all the 
lands which are appropriated to agriculture ; but the hand 
of man and the successive generations of plants have 
rendered them still better suited to this purpose. 

The great stones which injured the harvests upon allu- 
vial soils, have been removed by blasting. The soils 
which were too stiff have been improved by a suitable 
admixture of other earths ; all the soils have been in turn 
manured by the remains of plants, or the collections of 
the barn-yard ; and man has learned by experience what 
kind of culture, and what species of plants are suited to 
each soil. Nature has prepared the materials, man dispo- 
ses of them in such a manner as to cause them to produce 
according to his necessities, or his tastes. 

But in what does the difference of soils consist ? and 
which are those best suited to agriculture ? 

In examining the nature and variety of the rocks, of 
which all arable lands were originally but the ruins ; and 
which, notwithstanding all the labor of man, preserve their 
primitive characters, we shall find the following varieties. 

Amongst rocks of the first formation, or, as they are call- 
ed, primitive rocks, granite holds the first rank ; it is gene- 
rally formed by the aggregation, more or less compact, of 
several stones, differing among themselves in form, color, 
hardness, and composition ; these stones are, most com- 
monly, feldspar, quartz, and mica. These elements of 
granite, also, separately form rocks, in which only two 
of them are combined, as in micaceous schist, which is 
composed of quartz and mica, disposed in beds, sometimes 
curvilinear ; quartz forms by itself, nearly without mix- 
ture, some of the primitive mountains. 



FORMATION OF ARABLE LANDS. , 23 

I shall confine myself to these two species of rock, be- 
cause the others are not so widely extended over the globe, 
nor do they present themselves in as large masses as these. 
Neither shall I speak of some substances that are found, 
more or less, in granite, as hornblende, amphibole, serpen- 
tine, &.C., as these bodies are only secondary there. 

The composition of the various stones which constitute 
granite, is widely different ; quartz is almost entirely 
formed of siliceous earth ; feldspar of silex, alumina, lime, 
potash, and the oxide of iron ; mica contains besides these, 
magnesia. So that when granite is decomposed, it produ- 
ces those lands which, upon analysis, afford all these prin- 
ciples ; whilst the washings from the quartz mountains 
form only beds of siliceous earth ; and the ruins of rocks 
of micaceous schist contain only the elements of feldspar 
and mica. 

The calcareous mountains, composed of carbonate of 
lime, without any appearance of the remains of organized 
bodies, are ranged by naturalists amongst primitive rocks, 
and give rise to the formation of calcareous soils. 

AH the lands which are produced by the destruction of 
primitive rocks are of the first formation, and ought to be 
so designated to distinguish them from those which owe 
their existence to other causes, of which I am now 
about to speak. 

Independently of those causes which I have just ex- 
plained, and which have produced the formation of the 
greater part of the arable lands, there are others to which 
some lands owe their origin. The successive destructions 
which the whole surface of the globe appears to have suf- 
fered ; the decomposition of pyritous beds, which appear 
to have covered a part of it ; the numerous lakes which 
have disappeared by the hand of man, or by the acciden- 
tal rupture of their natural confines ; the eruption of vol- 
canoes ; the overflowings of the sea ; the bony remains of 
animals, and the decay of vegetables buried in the ground, 
have formed soils of all characters ; and these have after- 
wards been applied by man to his own use. 



24 CHYMISTRY APPLIED TO AGllICtJLTURE. 

ARTICLE IV. 

Of the Composition of Arable Lands. 

It would be easy to ascertain the nature of any portion 
of arable land, if we had to consider only the character of 
the rock from which it was produced ; but vegetation, 
time, and the labor of man, have wrought so many changes 
in it, that the primitive character has nearly disappeared; 
and it is necessary to judge of, and appreciate it in its 
actual state. Still, the lands devoted to agriculture are 
generally composed of silex, lime, and alumina ; with 
these are intermixed pebbles or sand of different natures, 
and in various proportions, and the remains of animal and 
vegetable matter, more or less thoroughly decomposed. 
The other substances which, by analysis, are found in 
these soils, are not in sufficient quantities to be classed 
amongst their elements; when these are too abundant, 
as is the case in certain localities with magnesia and the 
oxide of iron, the soil becomes less fit for vegetation. 

The best basis for good lands is a mixture of lime, 
silica, and alumina ; but, in order that they may possess 
all the desirable qualities, it is necessary that certain pro- 
portions, which an analysis of the best lands has made 
known, should be observed in the mixture. 

I propose, in the first place, to examine in what propor- 
tions the constituent principles enter into those lands, 
which are the most favorable to vegetation, and afterwards 
to ascertain the properties peculiar to each kind of soil ; 
and to enlighten the agriculturist as to the best methods 
of correcting the faults of one, by the qualities of another. 
I shall then treat of the effect produced upon the fertility 
of soils, by the accidental deposits of animal and vegeta- 
ble matter, which are mingled with them ; and I shall 
conclude by a short exposition of the means which can be 
employed by the agriculturist, for becoming acquainted 
with the nature of his lands. 

In order to know the earthy composition of those soils, 
which have been considered the most fertile in various 
climates, I shall have recourse to the analyses .of them 
which have been made by men worthy of the utmost con- 
fidence. 



FORMATION OF ARABLE LANDS. 25 

Bergmann found that one of the most fertile soils in 
Sweden contained 

Coarse silex .... 30 parts 

Silica 26 

Alumina 14 

Carbonate of lime ... 30 

100 

Giobert analyzed a portion of fertile soil from the neigh- 
bourhood of Turin, in which the principal earths were in 
the following proportions, 

Silica 77 to 79 

Alumina 9 to 14 

Carbonate of lime . . 5 to 12 
The most fertile mixture produced by Tillet, in a great 
number of experiments which he made at Paris, was com- 
posed off of clay, f of finely pulverized limestone, and | of 
sand. Upon reducing these to their elements, we find 

Coarse silex 25 

Silica 21 

Alumina 16.5 

Carbonate of lime 37.5 

An excellent soil for wheat, in the neighbourhood of 
Drayton, in Middlesex, gave ^ of siliceous sand ; the re- 
maining f were composed of three earths finely divided, 
in the following proportions. 

Carbonate of lime .... 28 

Silica 32 

Alumina 39 * 

I do not speak of the water, nor of animal and vegetable 
remains contained in the soil, and which enter into its 
composition in the proportion of about y\j. 

I have myself analyzed a very fertile soil formed by the 
alluvions of the Loire, at a distance of three hundred and 

[* Davy {AgricultuToL Chemistry, p. 162,) states this analysis 
thus, Parts. 

Carbonate of lime ....... 28 

Silica 32 

Alumina ......... 29 

Animal or vegetable matter and moisture . . .11 

— Tr.] 
3 



^26 CHYMISTRY APPLIED TO AGRICULTURE. 

seventy-five miles from its source, and found i^ composed 
of 

Siliceous gravel 32 

Calcareous gravel 11 

Silica 10 

Carbonate of lime . . • . . 19 

Alumina 21 

Vegetable remains 7 

The analysis of a soil in Touraine, which produced 
excellent hemp, gave me of 

Coarse gravel 49 

Carbonate of lime .... 25 

Silica 16 

Alumina 10 

From the results of these analyses we find, that in the 
best earths there is a large proportion of gravel, which 
renders the soil light and easily worked, and facilitates 
the passing off of superabundant rains. In consulting the 
analysis of less fertile soils, we find that their fertility 
diminishes in proportion as one or the other of the three 
principal earths predominates ; and becomes almost noth- 
ing in those which possess the properties of but one. 
The mixture of earths then is necessary to the formation 
of a productive soil ; and their proportion can be varied 
only according to the nature of the climate, and the 
kind of plant to be cultivated. Siliceous and calcareous 
earths may form a larger proportion of the soil in moist, 
than in dry countries, and alumina may, in its turn, pre- 
dominate in those lands, which, from their declivity, 
suffer the water to flow off freely ; but a mixture of the 
three earths can alone form a good soil, and too great a 
disparity in their proportions materially affects the char- 
acter of it. 

The constituent parts of a soil have a constant tenden- 
cy to become pulverized, and at length, by frequent tilling, 
by the action of salts, manures, and frosts, they are reduced 
to so fine a powder, as to cease to be productive. Rain 
falling upon ground in this state renders it perfect mud, 
which when exposed to heat becomes so hard, that the air 
cannot penetrate it, nor the tender fibres of plants force 
their way through it. 

Davy has observed, that all soils composed of ^§ of im- 
palpable matter are completely barren. The use of barn- 



Silica. 


Lime. 


Alumina 


48 


37 


15 


68 


26 


6 


69 


16 


15 


. 63 


21 


16 


4 


66 


30 


37 


33 


30 



FORMATION OF ARABLE LANDS. 27 

yard manure will correct for a short time only this state of 
a soil, and it is better to mix with it the sand, and coarse 
gravel, which are necessary to restore it to fertility. 

It appears that the three earths, which form the basis of 
the most fertile soil, enter into the composition of plants; 
Bergmann has proved this by analysis of several kinds of 
grain ; and Ruckert by the results of his experiments 
upon a variety of vegetable productions, in a way to put 
it beyond doubt. About 100 parts of ashes well 
leached, and consequently disengaged of all their salts, 
yielded 

Ashes of wheat . . 
" of oats 
** of barley 
•* of rye 
" of potatoes 
" of red clover 
All soils are not composed of the mixture of the three 
most important earths ; some of them are formed by the 
union of two, as of silica with alumina, or of carbonate 
of lime with alumina, 6lc., and we occasionally find each 
one of tnem combined separately with qu-^rtzeous or cal- 
careous gravel, forming land Vvhich may be cultivated. 

It is seldom that the soils of which we have spoken in 
the preceding paragraph, are composed solely of the two 
substances referred to ; but these so far exceed in impor- 
tance all the others which enter into the mixture, as to give 
a character to the whole, which the latter cannot much 
affect. 

The mixture of silex with alumina forms that soil called 
clayey, argillaceous, or simply claT/. The properties of 
the alumina predominate in all clayey soils, which are 
less fertile in proportion to the increased quantity of it 
which they contain ; when it equals or exceeds one half, 
they are only fit to be employed as the basis of some kinds 
of earthen ware ; especially if the other moiety consist of 
silex finely pulverized. 

I have had occasion to analyze three specimens of clay 
taken from three fields situated upon a plain, formed al- 
most wholly of argillaceous marl ; the first afforded 

Silex in grains 17 

Alumina 47 

Silica 21 



28 CHYMISTRY APPLIED TO AGRICULTURE. 

Carbonate of lime .... 10 
Carbonate of magnesia ... 3 

Oxide of iron 2 

The second 

Silex in grains 22 

Silica 15 

Alumina 45 

Carbonate of lime . . . . 11 

Carbonate of magnesia ... 4 
Oxide of iron ...... 3 

The third 

Silex in grains 19 

Silica 24 

Alumina 40 

Carbonate of lime .... 9 
Carbonate of magnesia ... 5 

Oxide of iron 3 

The other principles were the remains of manures part y 
decomposed. These three portions of soil were from land 
which produced but little. The water which stands upon 
clayey soils is always turbid and whitish, especially when 
agitated by the winds ; heat has the effect of chapping 
and splittincr these soils, and hardens them so, as to ren- 
der them nearly impenetrable to the plough ; in order to 
give them fertility it is necessary to employ a great deal of 
undecomposed barn-yard manure and litter ; and it is 
advisable to sow, in the spring, crops of buck-wheat. 

The soils which are formed of the waste, or from the 
decomposition, of mountains of calcareous free-stone, or 
of the carbonate of lime, whether primitive or secondary, 
frequently present only a mixture of calcareous sand, of 
which the grains are united by a carbonate of the same 
nature. These earths are in general light, porous, and 
well suited to many kinds of cultivation, especially in 
rainy climates, provided the bed be of sufficient depth, 
and formed upon a basis of rock, to enable it to retain 
the quantity of water required by the wants of vegetation ; 
they are well adapted to the cultivation of the vine, and of 
sainfoin ; and when they can be well manured will produce 
good crops of rye, oats, and barley. These soils have re- 
ceived the name of calcareous, though they almost always 
contain other principles, because the properties of the 
carbonate of lime predominate so much over those of the 
other substances, that the latter are hardly perceived. 



FORMATION OF ARABLE LANDS. 29 

The mixture of alumina and lime constitutes another 
species of soil, which by itself is but little productive, 
especially if alumina constitutes more than one half of it; 
but it is used with great advantage in improving some 
other kinds of land. The soil formed from this mixture 
is called marl, or a marly soil ; the nature of it varies 
much, according to the difference in the proportions of its 
constituent principles ; it is called clayey, or fat, when 
the qualities of alumina predominate in it, and calcareous, 
or poor, when the calcareous sub-carbonate gives it it9 
character. Marl often contains shells, whole beds of it 
being sometimes formed almost entirely of their ruins ; the 
"fakluns " * are of this species ; this is the poorest kind, 
and the most suitable for improving argillaceous soils. 
The fat marl is often mingled with siliceous sand, which 
serves to enhance its value when used in amending light 
and calcareous earths. I have seen marl containing y^^ 
of sand, -f^-^ of alumina, and ^Wu ^^ carbonate of lime, 
used with advantage upon soils purely calcareous. 

Marl is usually found in beds, buried at a slight depth 
in the earth ; when taken out and exposed to the air it 
presents appearances which vary according to its quality. 
Under the combined influence of air and water, it is 
generally reduced to powder ; but the decomposition is 
much more speedy and complete, when the two earths are 
in their proper proportions, than when either of them pre- 
dominates. 

The action of water dissolves, and carries off the alu- 
mina gradually, the carbonic acid of the atmosphere com- 
bines with the lime, which remains unsaturated, whilst 
the oxygen acts upon the iron, increasing its oxidation, 
till an entire change is produced in the nature of the 
earth, which acquires properties before strangers to it ; it 
becomes pulverulent, and it is in this state that it is used 
to fertilize other earths. 

When marl is very argillaceous, it may be hardened by 
the action of fire, and it then becomes sonorous, like well 
baked potter's ware ; when it is very calcareous, fire con- 
verts it into lime ; and I have seen it in Cevennes forming 
an excellent mortar when combined with a sufficient quan- 
tity of sand. 

There is an immense difference in the proportions in 

[* Probably " muschelkalk," or variegated marls. — Tb] 

3* 



30 CHYMISTRY APPLIED TO AGRICULTURE. 

which the two earths combine to form marl. Numerous 
analyses have been made by me of the marls of the cen- 
tre and south of France, and I have found them to con- 
tain from 10 to 60 per cent, of sub-carbonate of lime, 
from 15 to 50 of alumina, and from 15 to 66 of siliceous 
sand. Marl is often produced by the decomposition of 
silex or flint. 



ARTICLE V. 

Of the Properties of the different Earths. 

As the several earths contained in the soils of which I 
have just spoken, do not all possess the same qualities, and 
are very differently affected by air, water, and heat, the 
most powerful agents of vegetation, the excellence of a 
soil depends upon its containing the right proportion of 
each species of earth ; and that is supposed to be the best 
soil, in which the virtues of one portion of its constituent 
principles correct the faults or defects of the rest. In 
order to produce these mixtures, to supply the deficiencies 
of poor soils, and to be able to render them, by art, suita- 
ble to the production of some particular article of cultiva- 
tion, it is necessary to know the particular properties of 
each kind of earth ; and it is upon this subject that I shall 
now speak. 

Siliceous earth, or silica, exists in all hard primitive 
rocks, and forms nearly the whole of quartzeous moun- 
tains. In order to obtain it in its greatest degree of purity, 
it is fused with six parts of potash ; it is then dissolved in 
water, and separated from the alkali by muriatic acid ; the 
solution is evaporated to dryness, and the residuum wash- 
ed in water affords pure silica. In this state silica has 
the appearance of a white impalpable earth, rough to the 
touch ; when thrown into water it sinks with extreme 
rapidity, but its particles have no tendency to unite into 
one mass. The weight of silica compared to that of water 
is 2.5 to 1.* 

[* Silica exists pure in rock crystal, and nearly pure in flint. It 
may be obtained pure by heating rock crystal to redness, quenching' 
it in water, and reducing it to a fine powder. Fuse 1 part of this 



fHOPERTIfiS OF DIFFERENT EARTHS. 31 

The only acid which has been found to act upon silica 
is the fluoric, and this will disengage it from glass, of 
which it is one of the constituents. Hot alkaline lixivia 
act slightly upon it. It is found abundantly in plants, 
where it could only be introduced in a state of extreme 
division, or by being dissolved in some alkali. 

This earth undergoes no change from the action of fire 
or air, because it is saturated with oxygen ; according to 
the analysis of Davy and Berzelius, it is composed of equal 
parts of oxygen, and of a basis called silicium. 

According to my experiments, this earth, though dry 
and impalpable, absorbs scarcely ^ of its own weight of 
water, and permits it to escape by evaporation in ^ of the 
time in which carbonate of lime, equally divided, parts with 
it ; and in ^ of the time, in which it escapes from alumina 
in the same state. 

All the compound primitive rocks contain alumina ; in 
order to obtain this pure, it must be precipitated, by the 
carbonate of ammonia, from a solution of alum, of which 
it forms the basis ; the precipitate must be washed, and 
ignited, and the residuum is perfectly pure alumina ; it is 
always in the form of a white powder, and possesses the 
following characteristics. 

It is very astringent.* 

Its specific gravity is from 2.2 to 2.3. 

It is hardened by fire, and undergoes, by the action of 
it, a change which destroys its solubility in water. 

It absorbs water with great avidity, not being saturated 
with less than 2.5 of its own weight, and retains it very 
forcibly, especially when that which softened its surface is 
evaporated ; yielding it entirely only at a temperature suf- 
ficiently high to produce fusion. 

Alumina saturated with water forms a soft paste, smooth 
to the touch, easily moulded, and receiving without diffi- 
culty any form which one may wish to give it. 

According to the analysis of Berzelius, alumina consists 
of 46.70 of oxygen, and 53.30 of a/wwmww. 

powder with 3 of potassa in a silver crucible, and evaporate to dry- 
ness. Wash the mass in boiling distilled water, upon a filter, and the 
white substance which remains is pure silica.t Its color is white ; its 
specific gravity 2.66. — Tr.] 

[* Brande {Manual of Chymistry) says it is tasteless. — Tr.] 

[t This is the usual process, but the silica always retains potassa, and the earth ob- 
tained by simply reducinpthe colorless rock crystal to powder is more pure. (Brande s 
Jdanucd of Chymistry, p. 235.)— Tr.] 



3S CHYMISTRY APPLIED TO AGRICULTURE* 

Lime is found in nearly all primitive rocks, and forms 
the basis of all calcareous mountains, whether primitive 
or secondary. 

It is obtained pure by calcining, at a high temperature, 
Iceland spar, primitive marble, etc., or by precipitation 
from a solution of them in an acid. Its taste is acrid and 
caustic. It absorbs water with avidity, and with a hissing 
noise, and forms with it a hydrate, or a paste which is the 
basis of mortars. Carbonic acid, for which it has a strong 
affinity, combines with it, separating it gradually from the 
water, which evaporates. Pure lime is composod of 28.09 
of oxygen, and 71.91 of calcium. 

The lime which is found in lands appropriated to agri- 
culture, is in the state of a carbonate, and possesses char- 
acteristics very different from those of its pure state. Its 
specific gravity is 2.0. The pulverized carbonate absorbs 
0.8 of its own weight of water, and retains it less forcibly 
than alumina does. 

The mixture of these earths has the general character 
which results from the union of the qualities, which each 
earth brings into the composition of the soil ; but inde- 
pendently of the action which these principles exercise 
upon each other, air, water, labor, and the use of manure, 
produce modifications of the soil which it is important for 
us to understand. 

It is my intention to examine the influence which all 
these agents exercise over the various soils, and I enter 
upon the discussion with the more interest, because it 
furnishes to the aorriculturist reasons for the methods he 
has pursued ; and explains to him many phenomena which 
he has observed, but for which he could not account. 

We have already seen that the atmosphere furnishes to 
plants two of their constituent principles ; of which one 
(carbonic acid) contributes to their support by the carbon 
which it deposits in them, whilst the other (oxygen) 
takes from them a portion of carbon ; this last becomes 
again the principal agent in the decomposition of manures 
and dead vegetables ; but the action of air is not confined 
to the performance of these offices, however important 
they may be. 

The air may be considered as a vehicle constantly 
loaded with a quantity of water in vapor, of which the 
coolness of the night causes it to deposit a part upon the 
earth. The surface of the ground and the leaves of plants 



PROPERTIES OF DIFFERENT EARTHS. 33 

are often moist in the morning ; the return of the sun and 
the heat of the day evaporate this liquid, to be deposited 
again at sunset, and during the night; thus by an alternate 
movement, determined by the changes in the temperature 
of the atmosphere at different periods of the twenty-four 
hours, water is constantly applied to plants, to preserve 
them from the excess of heat, which would wither, and 
dry up their organs. 

The aqueous vapors suspended in the air begin to be 
condensed and precipitated at sunset, and with them is 
deposited the greatest part of the emanations which have 
arisen from the earth during the day ; these exhalations, 
though beneficial to vegetation, are almost always injurious 
to man, and it is not withoiit reason that he fears and 
shuns the night damps. In southern climates, where the 
heat of the sun is more intense, and rains less frequent 
than in northern, vegetation is supported by the dews, 
which are very abundant. In order that the dews of night 
may produce their best effects upon vegetation, it is neces- 
sary that the soil should unite certain qualities, which it 
does not always possess. 

When the soil is hard and compact, and forms by the 
action of the air an impenetrable crust, the dew is deposit- 
ed upon its surface, and evaporated by the rays of the 
sun, without having moistened the roots of the plants, or 
softened the earth around them ; so that, of the organs that 
serve to convey nourishment to the plants, the leaves are 
the only ones benefited by the dew, while the roots, which 
are the principal vehicles of nutriment when the plant is 
fully developed, are not in any degree benefited by it. 
It is necessary, in such cases, that the soil should be soft- 
ened, lightened, and divided, so that the air may convey 
the water with which it is charged, to the roots of the 
plants, and to every part of the earth surrounding them, 
to a certain depth ; then the plant can imbibe, through all 
its pores, the reviving moisture ; and that which is received 
by its roots is more lasting than that which it absorbs in 
any other way, because the roots being sheltered from the 
direct rays of the sun, evaporation takes place less rapidly, 
and the moisture is retained, whilst the leaves are speedily 
dried by the heat. Besides, that earth which is most 
easily affected by the dews, yields most readily to the 
action of roots, whether it be to fix the plant firmly by 
their extension, or to draw from the soil its nutritive prop- 
erties. 



S4i CHYMISTRY APPLIED TO AGRICULTURE. 

This explains in a natural manner the origin of a cus- 
tom observed by all agriculturists, and of which all ac- 
knowledge the advantage. When vegetables, such as 
peas, beans, potatoes, and other roots are sowed in fur- 
rows at equal distances from each other, the soil in the 
intervals is hoed, or dug, with the utmost care, and thus 
rendered light, soft, and permeable to the air, whilst at 
the same time weeds, which would be hurtful to the culti- 
vated plant by depriving them of nourishment affoided by 
the ground, are destroyed ; and the soil rendered more fit 
to receive the rain, and convey it to the roots. I do not 
deny that these benefits are real, but I hold them to be 
secondary, and subordinate to the advantage derived from 
opening access to the air, and permitting it to deposit its 
dews upon the roots, and upon the earth in contact with 
them. 

I have uniformly observed the effect of this method to 
be equally speedy and favorable in the cultivation of beet 
roots, and I have never employed any other, to restore their 
vegetation to its freshness when it becomes yellowish, and 
drooping ; in three or four hours it will become of a beau- 
tiful green, and the leaves spread themselves out, although 
no rain may have fallen ; and this often when the soil had 
not contained a single weed. I have observed the same 
effect produced upon the other culinary roots. 

A custom which is universally practised in the south of 
France, attracted my attention for a long time, without 
my being able to account for it. In that country, where 
it hardly ever rains during the summer, the foot of each 
setting of the vine is laid bare by digging around it a cir- 
cular trench, deep, and wide enough to contain uncovered 
the stump, and the radicles proceeding from it ; and the 
opening is speedily covered over by the leaves and branch- 
es. It is evident that this method has no other advantage 
than that of facilitating the access of the air to the roots, 
that it may deposit there the dew with which it is more 
abundantly charged than in cold climates; if it were not 
thus, this practice would expose the vines to be dried up 
by the scorching heat of the sun. 

All soils have not the same affinity for water, which arises 
from their different degrees of tenuity, or the division of 
their particles, and from the nature of the substances which 
enter into their composition. In general, the more finely 
the parts of a soil are divided, the better they absorb 
water 



PROPERTIES OF DIFFERENT EARTHg. 35 

The absorbing powers possessed by the elements com- 
posing a fertile soil, may be arranged in the following 
order. 

Vegetable substances. 

Animal substances. ' 

Alumina. 

Carbonate of lime. 

Silica. 

Alumina, and those soils where its characteristics pre* 
dominate, do not receive the moisture from the atmosphere 
to the greatest advantage ; they retain the water, which 
they imbibe, with so much force, that the plants produced 
upon them suffer as much from drought as if they grew 
in sand. 

The light porous earths, composed of sand, carbonate 
of lime, silica, and decomposed animal and vegetable sub- 
stances, in just proportions, are the best for absorbing and 
retaining moisture, in order to transmit it, with regularity 
and beneficial effect, to the plant. 

The experiments conducted by Davy have produced re- 
sults of great importance to agriculture ; he has compared 
the energy with which various soils absorb humidity from 
the atmosphere, and has uniformly found, that the most 
fertile possessed this power in the highest degree ; so much 
so, that the fertility of soils might be estimated, and class- 
ed according to it. 

1,000 parts of a celebrated soil from Ormiston, in East- 
Lothian, which contained more than half its weight of 
finely divided matter, of which 11 parts were carbonate 
of lime, and nine parts vegetable matter, when dried at a 
temperature of 212° Fahr., gained in an hour by exposure 
to an atmosphere saturated with moisture at a temperature 
of 62°, 18 grs. in weight. 

1,000 parts of a very fertile soil, formed by the deposits 
of the river Parret, in Somersetshire, gained 16 grs. 

1,000 parts of a soil from Mersey, in Essex gained 13 
grs. ^ 

1,000 grains of a fine sand from Essex gained 11 grs. 

1,000 grains of a coarse sand gained only 8 grs. 

1,000 grains of the soil from Bagshot-heath gained but 
3 grs. 

The absorbing power of a soil has always been found 
to be in proportion to its fertility, and to the excellence of 
its situation. 



86 CHYxMISTRY APPLIED TO AGRICULTURE. 

It is of the utmost importance in the science of agri- 
culture, that the comparative powers of the various soils 
for absorbing atmospheric moisture, and the degrees of 
force with which they retain it, should be ascertained. 
The means necessary to be employed in ascertaining these 
capacities of soils, are in the power of every cultivator ; 
he has only to dry thoroughly the same weight of each 
soil in a state of equal division, and to weigh them night 
and morning for several days, and he will be able to form 
an estimate of the quantity of moisture which each has 
imbibed durinor the nicjht. In order to obtain these results 
with exactness, it is necessary that the assays should be 
made upon equal weights of earth, in an equal state of 
division, equally dried, and spread in layers of an equal 
deorree of thickness. 

From the statements which I have made, it is easy to 
be perceived, that air and water are two powerful agents 
in promoting vegetation; they act upon it directly, by 
furnishing from their own decomposition nutritive princi- 
ples ; and they act as auxiliaries, by serving as vehicles 
for the conveyance into the organs of plants of such sub- 
stances as are necessary for their support. 

But though the plant is furnished with aliment through 
these agents, it is heat alone, that, by anitnating the vege- 
table organs, enables it to elaborate within itself the 
nourishment which it receives. The effect of temperature 
is perceptible not only in plants, but in many classes of 
animals ; nearly all insects are benumbed by the cold, 
and reanimated by the heat. 

All soils are not equally capable of receiving and retain- 
ing heat. The white earths are warmed with difficulty ; 
when pipe clay or aluminous marl predominates in a soil, it 
is nearly always damp, and retains but little heat. White 
chalky soils require much heat to warm them ; but they 
part with their heat less quickly than the first, whilst col- 
ored earths absorb heat, in propoition as the depth of 
their hue increases from brown to black. 

Davy has remarked that a black soil containing nearly 
■I of vegetable matter, when exposed to the sun, acquired 
in one hour an elevation of temperature which raised the 
thermometer from 65° to SS'', whilst under the same cir- 
cumstances, a soil whose basis was chalk, raised it only 
to 69 degrees. When the black earth was carried into 
the shade at the temperature of 62°, the thermometer fell 



PROPERTIES OF DIFFERENT EARTHS. 37 

15° in half an hour, and the chalky earth lost by the same 
exposure 4°, 

Equal quantities of fertile brown soil,^ and of sterile 
clay, were dried ; and their temperature raised to 88° ; upon 
being then exposed to air at the temperature of 57°, the 
brown soil lost, in the space of half an hour, 9°, and the 
clay 6° ; moistened clay at 88°, exposed to a temperature 
of 55°, fell to the same in less than a quarter of an hour.* 

The variations of temperature in soils of different na- 
tures, with their several degrees of affinity for heat, and of 
power for retaining it, deserve the attention of the agri- 
culturist. The only instrument necessary for conducting 
experiments upon this subject, is a good thermometer ; and 
by the aid of that we can ascertain the kind of soil suited 
to any one species of plant, since all do not require the 
same intensity, nor the same continuance of heat. 

The different degrees of heat which earths imbibe at 
the same temperature is known to most agriculturists, and 
many of therri^ turn the knowledge to advantage. It is 
customary with those who cultivate the table lands upon 
the sides of the Alps, to throw black earth upon the snow, 
in order to hasten its thawing, that they may commence 
their cultivation as soon as the sun returns to them. The 
same means are employed in green-houses and orangeries ; 
the walls are blackened, and the soot spread over the soil 
serves to concentrate and fix the heat, to such a degree, 
that in the month of July, upon the Cramont, at an eleva- 
tion of 9077 feet, where the temperature was at 43°, M. 
Saussure found that a thermometer which was placed in a 
box lined with blackened cork, and of which the opening 
was closed by three glasses placed at some distance from 
each other, rose in two hours from 38° 75' to 99° 50'. 

Independently of the heat which the atmosphere com- 
municates to the soil, and of the modifications wrought 
upon it by the color of the constituent principles, it is in 
the power of art to lessen or to increase the temperature of 
lands at will. Animal manures develope more or less 
heat, according to their nature, and their state of fermen- 
tation ; those which have not been decomposed, excite 
more heat, and maintain it for a longer time, than others. 

[* See Davy, p. 179, 180. Chaptal has reduced his degrees erro- 
neously, and they are corrected as above from Davy's Agricultiiral 
Chemistry. — Tr.] 



38 CHYMISTRY APPLIED TO AGRICULTURE. 

The excrement of the sheep and horse is more heating in 
its action than that of cows; the black or brown manures 
warm the soil more than marl or chalk. 



ARTICLE VI. 



Of the Properties of Mixed Earths, and the Methods of 
rendering them capable of a good Cultivation. 

I BELIEVE that I have sufficiently explained the origin 
of soils, their composition, and their influence upon vege- 
tation ; whether it be exerted through their constituent 
principles, or by the effects which are produced upon 
them by air, heat, &/C. ; it now remains for me to speak 
of some circumstances which modify soils, and with which 
the agriculturist ought to be acquainted. 

I have repeated several times in this chapter, and in 
that in which I have spoken of manures, that the results 
of the decomposition of animal and vegetable substances, 
concur with the constituent principles of air and water to 
form the food of plants; I have remarked, that plants be- 
ing immovable, it was necessary that these supplies should 
be presented to them, and in a state which would admit of 
their being readily absorbed by the fibres of the plants ; 
to these observations I have added, that heat animates 
plants, and gives to their organs the power of decompos- 
ing these substances, and, from the elaboration of them, 
of forming all the products of vegetation. 

In order that plants should derive the greatest advantage 
from their means of support, it is necessary, that their 
nourishment should be supplied to them in proportion to 
their wants, and consequently, that the decomposition 
which the greatest part of these aliments must undergo, 
should neither be too speedy nor too moderate ; tiie soil 
appears to be the principal agent in producing these modi- 
fications, and serves to regulate the others ; it forms a 
magazine, in which are deposited nearly all the aliments 
of plants, and it ought to possess all the properties requi- 
site for supplying the wants of vegetation. 

The characteristics which mark each one of the earths 
which constitute a soil, concur by their union to produce 
this effect; chalk and silica retain but little water, but 



PROPERTIES OF MIXED EARTHS. 39 

their mixture with alumina preserves plants from suffering 
so often from drought ; without the presence of ahimina, 
they would be alternately inundated, and dried up. Clay 
alone does not permit the roots of plants to extend them- 
selves, nor allow the air to penetrate to them ; but mixed 
with silica, carbonate of lime, and sand, it forms a porous 
soil, which possesses these properties. Chalk preserves 
animal and vegetable substances from a too rapid decom- 
position. Alumina and the oils combined together pro- 
duce a saponaceous mixture, which can be imbibed by 
plants, and thus furnishes them with two principles, which 
separately are insoluble in water. 

The composition of soils varies according to the differ- 
ence in climate, otherwise their fertility would be les- 
sened. The quantity of rain that falls is so various, that 
even within the extent of France, it ranges, according to 
situation, from twenty to thirty, and according to Giobert, 
at Turin, to thirty-four inches. There are some countries 
where the atmosphere is almost always cloudy, and the air 
laden with moisture ; w-hilst there are others in which the 
sun is not obscured for six months together. It is evident 
that in those countries where the air is uniformly damp, 
and in t-;ose where rain is abundant, the soil may be, with- 
out inconvenience, more calcareous than argillaceous ; and 
that the best soils in the two divisions would differ very 
widely as to the proportions in which their several earths 
would be combined. 

Soils should vary according to the nature of the plants 
to be cultivated in them ; some prefer a porous, dry, and 
arid soil, others flourish only in land constantly moist; 
there are some that require a great degree of heat, others 
vegetate in the midst of snows. These peculiar tastes of 
plants ought to be known to the agriculturist, that he may 
select for each one the soil best adapted to it ; or change 
the characters of those he possesses, so as to afford to each 
plant the soil most congenial to it. 

In order that a plant should flourish in a soil, it is not 
always sufficient that the earths composing it are of the 
right kind, or suitably proportioned ; it is necessary to 
unite other circumstances which are not always to be met 
with ; for example, the arable soils which are based upon 
rocks, vary considerably in depth ; and the thickness of 
the bed not only exerts an influence upon the powers of 
vegetation, but determines the kind of plant which can be 



40 CHYMISTRY APPLIED TO AGRICULTURE. 

cultivated upon it. The bed of earth ought to be from 10 to 
12 inches in depth for grain, and much more than that for 
clover and sainfoin ; for trees it must be much deeper 
than for these, otherwise their roots, running but little be- 
low the surface of the ground, will extend their shoots to 
a great distance, and thus exhaust the strength of a large 
portion of soil. Trees are often found upon the sides of 
mountains, which are almost entirely devoid of a covering 
of earth, i3ut in this case the chinks and crevices of the 
rocks supply the place of earth, or rather the rocks are of 
so spongy and porous a nature, as to permit the roots to 
penetrate them. In the Cevennes and Limousin the 
most beautiful chestnuts are planted upon granite and 
free-stone ; and the famous vines of the Hermhage pros- 
per in a soil of granite decomposed at the surface. 

It is not immaterial of what substance the sub-stratum 
of the beds of earth are composed ; if it be of sand, the 
soil above will dry more quickly than if it were of marl or 
clay. A bed of clay under one of sand contributes to its 
fertility by retaining the water, which easily filters 
through the last, and thus preserving its humidity ; but if 
the water collected upon the clay moisten for too long a 
time the roots of the plants, they become languishing. I 
have always observed that roots might be exposed to living 
and flowing water, without being injured by it, but that 
stagnant water is always hurtful, and, for the most part, 
destructive to them. Agriculturists have learned this by 
experience, and hence has arisen the custom of draining 
their fields and meadows. In lands which are too moist, 
a good effect is produced by forming beds of flints, or peb- 
bles, upon which a layer of mould may be placed ; I have 
seen excellent meadows made in this way, upon land which 
had never before produced any thing but rushes. 

A clayey or marly soil, which lies upon a bed of calca- 
reous and porous rock, is more fertile than one which rests 
upon a foundation of hard rock, impermeable to water; 
the reason of this is very simple ; in the first case, the wa- 
ter filters through the rock, and escapes ; in the second it 
remains stagnant, rendering pasty a soil possessing none 
of the requisites for vegetation. 

The situation of land causes a great variety in its fertili- 
ty, and in the nature of its productions ; lands which have a 
southern exposure dry more quickly than those lying towards 



PROPERTIES OP MIXED EARTHS. 41 

the north, but vegetation is more active in the first than in 
the last, and the quality of their productions superior. 

The slope of lands likewise affects their fertility ; a 
piece of ground which lies upon a declivity, loses water 
more readily than one which is horizontal, and vegetation 
is less strong upon it, but the productions are of a better 
quality. There is a vast difference between wines made 
from the same kind of grape, raised in the same soil, if 
one be the production of the harvest upon the declivity of 
a hill, and the other of the plain at its foot. 

Inclined lands, where the slope is rapid, and the soil 
light and porous, are liable to the evil of having the ma- 
nures, applied to them, carried off by heavy rains; even the 
soil sometimes experiences the same fate, and the surface 
becomes furrowed, by ravines laying bare the rocky foun- 
dation. This frequently happens to lands cultivated upon 
the sides of mountains, till they become at length com- 
pletely barren; and hence we must conclude that it is 
unwise to clear up the declivities of mountains, since a 
temporary advantage reduces the land to a long period of 
sterility. 

Soils composed of the same earthy principles, combined 
in the same proportions, will still present very different 
results, according to the nature and quantity of the salts 
which they contain. I have made known those which are 
usually found in plants, and which for this reason must be 
regarded as suited to vegetation ; but their proportions are 
limited, and if they are too abundant, they become hurt- 
ful. The salts cannot be regarded as the actual food of 
plants; they are only auxiliaries, though very powerful 
ones, to their nutrition. The organs of vegetables require 
exciting ; and heat and the salts act upon them as stimu- 
lants. The salts are to plants what spices and marine 
salts are to man. Independently of their stimulating 
powers, the salts exert a chymical action upon the aliments 
of plants, by combining with them, rendering some of them 
soluble in water, and moderating the decomposition of 
others ; and thus contributing to regulate and facilitate 
the process of nutrition. 

Even from the part which the salts perform, it is evident 
that they ought to be supplied only in suitable proportions ; 
if they are too abundant, or very soluble in water, they 
will be absorbed by the organs of the plants in such a 
quantity as to produce irritation and dryness. Thus the 
4* 



42 CHYMISTRY APPLIED TO AGRICULTURE. 

best soil may be stricken with barrenness if the salts be- 
come too abundant in it. 

Thorough ploughing contributes largely to the fertility 
of lands ; but in order that it may produce its best effects, 
it is necessary to have regard to some circumstances 
which are generally but too little attended to. 

Ploughing divides and softens the soil, mixes thorough- 
ly its constituent principles, destroys weeds, and disposes 
them to decay ; and frees the ground from those insects 
which often abound in it. 

The ploughings should be more numerous, and con- 
ducted with more care, upon a heavy soil, than upon 
one which is light and porous. Clayey soils should be 
ploughed only when dry ; when they have imbibed water 
they form a soft paste, on which ploughing has no other 
effect than to trace furrows in the mud. Sandy and cal- 
careous lands may be ploughed at all times. Deep plough- 
ings are very advantageous to lands which are of the same 
nature to a considerable depth, since, in addition to the 
good effects arising from the operation itself, those parts 
of the soil which have become impregnated with the 
manures, that the rains have carried down below the sur- 
face, are thrown up to contribute to the nourishment of 
vegetation. Deep ploughings are likewise useful in those 
lands where the upper layer, being of too clayey and 
compact a nature, rests upon a bed of sand or carbonate 
of lime, which by this operation is brought to the surface 
and mingled with the upper layer, thus rendering it more 
fertile than it could be made by any other means. An 
equally good result is obtained from deep ploughing in 
the reverse case, that is, when a soil, too sandy or calca- 
reous, rests upon an argillaceous bed. 

But deep tillage does not belong to all soils, nor is it of 
use under all circumstances. For instance, if a soil is 
situated upon a vein of earth charged with black oxide of 
iron, or upon a bed of marl, the mixture which would be 
produced by deep tillage would reduce the land to almost 
entire sterility for two or three years. 1 have myself ex- 
perienced tthis result, and I speak from personal knowl- 
edge. Near a forest of oaks upon one of my estates, the 
land, which had been cultivated, was of an argillaceous 
character for about six inches in depth ; under this lay 
a bed of very dark brown earth, of five or six inches in 
thickness, and composed of silex, clay, and oxide of iron. 



PROPERTIES OF MIXED EARTHS. 43 

I caused the two beds to be broken up and mixed well 
together with the spade. The first year the harvest from 
it was almost nothing, much less than before, though it 
had never been fertile. The second year it was a little 
more productive ; but it was not till the fifth year that it 
recovered its usual degree of fertility. One of my friends 
possessed a piece of ground of a moderate degree of pro- 
ductiveness. The soil, which was sandy and very dry, 
was much improved by the application of marl, which he 
allowed to decompose upon it for two years before cultiva- 
tion. As the same person had a bed of marl in one of his 
fields at the depth of a foot, I advised him to break up a 
piece of it, twelve or fourteen yards square, and to mix 
the marl with the upper layer of earth, in a proportion 
more considerable than in the other case. The portion of 
the field thus operated upon was nearly barren for two 
years, after which it was more decidedly fertile than 
before. 

These two cases struck me very strongly. I sought for 
the reason of the changes, and believe that I have found 
it in the nature of the inferior layer of the earth at the 
time of being mixed with the upper soil. 

In the first case the oxide of iron, which colored the 
bed brown, was at the lowest state of oxydation ; but at 
the moment that it was brought into contact with the at- 
mospheric air, it began to combine with new portions of 
oxygen, and the earth could not become fertile till the 
iron was saturated. The progress of oxydation entirely 
changed the color of the soil ; from black it became of a 
deep lively yellow. This fact may admit of a different 
explanation. Is the oxide of iron, in its black state, de- 
structive to vegetation? Does that oxide, which, by at- 
tracting the oxygen from the atmosphere, decomposes it, 
destroy by its action the necessary and salutary influence 
of that fluid upon plants? These are questions which can 
only be answered by a long experience. 

In the second case the cause of sterility was differ- 
ent, though it had a general relation to that of the first. 
Marl is principally composed of sub-carbonate of lime and 
alumina ; the proportions in which these are combined 
constitute all its varieties. The lime contained in marl, 
as it is taken from the bed, is never saturated with car- 
bonic acid ; but after being exposed to the air, it becomes 
at length saturated with the acid it receives from it, 



44 CHYMISTRY APPLIED TO AGRICULTURE, 

crumbles, and effloresces. The decomposition of marl 
may be hastened by frequently turning it, so as to allow 
the air free access to the lime ; and this method is gene- 
rally practised by those who employ marl as a manure. 
The same questions may be proposed in regard to imper- 
fectly carbonated lime, as to the oxide of iron. 

When M. Fellenberg wished to verify his principles of 
cultivation upon his estate of Hofwyl, he had his land 
broken up to the depth of three or four feet, and it pro- 
duced nothing till the end of two or three years. 

These facts, and many others which I could cite, prove 
that it is necessary for earths, in order to possess great 
fertilizing powers, to be saturated with all the principles 
which they can imbibe from the atmosphere. Thus those 
which, by the depths of their beds, have been constantly 
secluded from the action of the air, will require to be 
exposed to it a long time before becoming fertile. Those 
who are engaged in agriculture know this fact, and ex- 
press it by saying that the air deposits its fructifying prin- 
ciples upon the earth. They use the expressions, — " The 
soil is not made enough ; is not ripe enough ; is not aired 
enough," &.c. This understanding of the subject is not 
very exact, but sufficiently so to direct their practice. 

When, by digging or deep ploughing, the mould has 
been mixed with these unsaturated earths, it ought to be 
stirred at long intervals by the plough or pick-axe, before 
being sowed. By presenting all the parts successively to 
the action of air and water, they are enabled to imbibe 
from them those principles in which they are deficient ; 
and thus the same effect is produced upon them, as is 
wrought upon marl or the black ferruginous earths by a 
longer exposure, after they have been taken from their 
beds. 



ARTICLE VII. 

Of the Analysis of Arable Soils. 

Though experience and long observation may enable ar¥ 
agriculturist to become acquainted with the nature and 
degree of fertility of each part of his land, it will in most 
cases be convenient for him to acquire this knowledge by 
shorter and more direct methods. 



ANALYSIS OF ARABLE SOILS. 45 

I shall not point out the process of an analysis with the 
most minute exactness ; this would place it beyond the 
skill of the greater part of agriculturists to perform ; and 
the precision of the results would be useless for the pur- 
pose which I have in view. I shall limit myself to de- 
scribing the steps which ought to be taken for ascertaining 
the nature of the principal substances, whether earthy, 
saline, metallic, vegetable, or animal, which enter into the 
composition of a soil, whilst it is necessary to insist only 
upon those which concur most powerfully in rendering it 
fertile. 

In analyzing an earth, a small quantity of it should be 
w^orked carefully by the hand before weighing it. The 
first operation consists in drying this specimen carefully, 
in order to know the weight of water it contains. For 
this purpose it is placed in a vessel over the fire, of which 
the heat must be just sufficient to evaporate the water. 
This temperature must be preserved from fourteen to 
twenty minutes. In order that no more heat than is 
necessary may be applied, it is customary to put a bit of 
wood at the bottom of the vessel, or a few bits of straw 
into the earth subjected to the experiment, and to with- 
draw it from the fire as soon as these begin to turn brown. 

The next operation is to weigh the earth a second time ; 
and the loss it has sustained will be equal to the weight of 
the water which has been evaporated. This operation 
does not determine exactly the weight of water contained 
in the earth, because one part of it is nearly solidified by 
its combination with some of the earthy principles, as 
alumina, the salts, and many other substances, animal 
and vegetable ; but it ascertains the quantity which served 
to moisten the earth. In performing experiments upon 
earths at a high degree of temperature, it is easy to ascer- 
tain the power which they have of absorbing moisture, 
and from this some judgment may be formed of their fer- 
tility. 

As soon as the quantity of free moisture contained in 
the earth is ascertained, the sample must be bruised in a 
mortar till it becomes only a collection of small particles. 
By means of shaking upon a sieve, the gravel and other 
hard substances, which enter into the composition, may be 
separated from the other matters, which, having been ren- 
dered finer, will pass through readily. The coarsest par- 
ticles should be assayed separately from the others; if 



46 CHYMISTRY APPLIED TO AGRICULTURE. 

they are calcareous, acids will dissolve them, producing 
at the same time an effervescence ; to prove this, a few 
grains of them may be put into a glass containing good 
vinegar, or muriatic acid diluted with three or four parts 
of water ; if they are composed only of carbonate of lime, 
they will be entirely dissolved, especially if the liquor 
should still preserve its sharp and sour taste ; for in all 
these experiments it is necessary to use an excess of acid. 

If the coarse particles do not effervesce with an acid, 
they are composed entirely of silica or alumina. These 
are easily distinguished from each other, the silica being 
rough to the touch, scratching glass, and sinking quickly 
in water ; whilst alumina is smooth and unctuous to the 
touch, and mixes with water, in which it remains some 
time suspended. 

The coarse particles may be composed by the union of 
the calcareous, siliceous, and aluminous earths: but in 
this case the acids have dissolved a part of the cnlcareous 
particles ; and, after removing the acid which holds them 
in solution, it is easy to ascertain by the abovementioned 
characteristics, whether the insoluble portion remaining 
in the glass be silica or alumina. 

If the coarse particles are only of quartzeous sand or 
of pure silica, water and the acids will produce no effect 
upon them ; and their nature can be easily determined 
by the characteristics I have given of silex and alumina. 

It sometimes happens that these coarse particles are 
mixed with the remains of animal or vegetable substances 
imperfectly decomposed ; but these will be easily recog- 
nized by the characteristics which distinguish fossil sub- 
stances. 

Nothing now remains to be done but to examine the 
finely divided and pulverulent soil, which passed through 
the sieve ; this contains the earths, salts, and animal and 
vegetable substances, in a state of minute division. In 
order to ascertain the nature and proportions of the prin- 
ciples contained in this mixture, it must be first weigh- 
ed, and then boiled in four times its weight of water, 
from ten to fifteen minutes ; the whole should then be well 
stirred, and left to settle ; a precipitate will soon be 
deposited, consisting only of the heaviest portions of the 
mass, usually of fine siliceous sand ; the turbid liquor 
which floats above being thrown on a filter, the earths 
and some salts not easily soluble remain upon the filter. 



ANALYSIS OF ARABLE SOILS. 47 

and the water charged with all the soluble portions flows 
into the vessel destined to receive it. 

We find, by this operation, three distinct products ; 
first, the precipitate deposited at the bottom of the vase 
in which the ebullition was performed, consisting of the 
finest sand ; secondly, that remaining upon the filter, 
and which consists of a mixture of earths and insoluble 
salts ; and, thirdly, that which contains in solution all the 
salts and animal and vegetable substances capable of 
being dissolved in boiling water. The two first, after 
they have been dried with care, and their weight ascertain- 
ed, must be examined in order to know the nature and 
proportions of the substances which compose them. 

I have previously observed, that the deposit constitut- 
ing the first product, is generally composed only of sil- 
ica ; if otherwise, it could be tested by acids, which will 
dissolve all the calcareous portions of it, while those parts 
which are insoluble may be treated by the means, which 
I have already pointed out, for separating alumina from 
silica. 

For the second part, which is the one remaining on 
the filter, it is sufficient to make an analysis of it, by 
pouring upon it muriatic acid diluted with four parts of 
water, till it will effervesce no longer ; this will dissolve 
the carbonates of lime, and of magnesia, should there 
be any present, as well as any oxide of iron ; the solu- 
tion being filtered, any substance not dissolved will re- 
main on the filter, and must be washed with water, till 
the water runs off tasteless ; the residuum must be dried 
and weighed ; it generally consists of alumina, and SDme 
animal and vegetable matter. 

In order to ascertain if the muriatic acid has dissolved 
any oxide of iron, stir it with a bit of oak bark ; if the 
liquor renders it brown or black, it contains iron ; in or- 
der to ascertain the quantity, throw into the liquor prus- 
siate of potash till it will no longer form a blue precipi- 
tate ; let it settle ; collect the deposit, and heat it to red- 
ness ; that which remains after this operation is the oxide 
of iron, and must be carefully weighed. 

When the solution has been freed from the oxide of 
iron, there remains in it only lime, and perhaps a little 
magnesia ; these can be precipitated by means of a so- 
lution of carbonate of soda, which must be poured into 
the muriatic acid till a precipitate is no longer throwa 



48 CHYMISTRY APPLIED TO AGRICULTURE. 

down ; after having poured off the liquor, the residuum 
must be washed and dried ; when its weight will give 
the quantity of carbonate of lime contained in the earthy 
mixture. 

If the carbonate of lime, and the other deposits ob- 
tained, be of a brown color, it is to be presumed, that 
they contain a mixture of animal or vegetable substance, of 
which the quality and proportions may be ascertained by 
throwing them upon a red-hot iron, and holding them over a 
fire of such a temperature, as will heat the iron to white- 
ness ; if the smoke arising from them have the odor of 
burning leather, hair, or feathers, the substance contained 
in them is animal ; but if it have the smell of wood smoke, 
it is vegetable. The two substances are sometimes com- 
bined, but the means of ascertaining in what proportions 
are beyond the skill of an agriculturist ; I have therefore 
thought that I ought to confine myself to the experi- 
ment necessary for ascertaining their presence. 

The method I have just described is easy, and in the 
power of any agriculturist, however little informed ; it 
is not exact, but it furnishes results approximating near 
enough to the truth, to enable any one to ascertain the 
nature and proportions of the earthy substances which 
enter into the composition of a soil. A greater degree 
of precision in the analysis would require the employ- 
ment of many agents unknown to the agriculturist, and 
a habit of analysis which he cannot be supposed to pos- 
sess. 

But as the salts play an important part in vegetation, 
and as all soils are in some degree impregnated with 
them, I believe 1 ought not to dispense with pointing out 
the means of recognising them, and for this purpose I 
shall be obliged to have recourse to some particular 
process. 

By boiling the finely divided earth in water, we can 
separate from it all the soluble salts it contains, and the 
evaporation of the liquid, which holds them in solution, 
will enable us to know their natures and proportions. 
If the operation be carefully conducted, the salts can be 
obtained in crystals, and, by the character of these, 
their properties can be distinguished. Nitre has a sharp 
taste, and consumes upon glowing charcoal ; marine salt 
decrepitates, and splits with a sparkling appearance over 
the fire ; the sulphate of soda swells up with the heat, 



NATURE AND ACTION OP MANURES. 49 

giving out an aqueous smoke, and leaving a dry white 
residuum. But when the salts are insoluble, as phos- 
phate of lime ; or soluble with difficulty, as sulphate of 
lime, water will not act upon them, and they remain 
mixed with the earth without their existence being sus- 
pected, as long as an analysis is confined to the limits I 
have laid down. However, these substances, especially 
the sulphate of lime, influence so much the quality of 
soils, that it is necessary to furnish the means for ascer- 
taining their existence. I will however observe, that 
these salts are contained in the earths in so small a 
quantity, as not to influence sensibly the results of the 
analysis I have directed, for ascertaining the natures and 
proportions of the other principles which essentially com- 
pose them. 

To ascertain if a soil contains sulphate of lime, (gyp- 
sum, plaster of Paris,) take an exact quantity, four hun- 
dred grains for example, mixed with one third the quan- 
tity of powdered charcoal, expose it in a crucible during 
half an hour to a red heat ; afterwards boil it for a quar- 
ter of an hour in half a pint of water, filter the liquor, 
and expose it for some days in an open vessel ; if it form 
a white precipitate, the soil contains sulphate of lime, 
and the weight of the deposit will make known nearly 
the proportion. (Davy.) 

To judge of the existence of phosphate of lime, digest 
the earth in an excess of muriatic acid, evaporate the 
solution to dryness, wash the residuum in a large quan- 
tity of water, and the insoluble phosphate will remain 
alone. 



CHAPTER III 

OF THE NATURE AND ACTION OF MANURES. 

Under the general head of manures are comprehended 
all those substances which, existing in the atmosphere or 
combining with the soil, can be drawn in by the organs 
of plants, and contribute to the progress of vegetation. 

Manures are furnished by various bodies belonging to 
the three kingdoms of nature. Those most commonly 
5 



50 CHYMTSTRY APPLIED TO AGRICULTURE. 

employed are the results of decomposed vegetable sub- 
stances, and some animal matters. 

The salts, which likewise serve for manures, are im- 
bibed by the pores of plants, and serve to stimulate vege- 
tation. 

By comprehending all these substances under the gene- 
ric name of manures, too extensive a signification is given 
to the word. I divide manures into two classes ; and in 
order to deviate as little as possible from the customary 
mode of expression, I shall call those nutritive manures, 
which supply plants with nourishment, and all those 
which excite the organs of digestion stimulating manures. 
These last are, strictly speaking, the seasoning; the 
spices, rather than the food. 



ARTICLE I. 
Of Nutritive Manures. 

The nutritive manures are those which contain juices 
or other substances, which, being dissolved in water, or 
otherwise divided to the most minute degree, are capable 
of being drawn into the organs of plants. All the vege- 
table and animal juices are of this description. 

These substances are rarely employed in their natural 
state for the aliment of plants. It is generally considered 
preferable to allow them to putrify or ferment ; the rea- 
son of this is simple. Besides the decomposition resulting 
from this operation, which renders the substances more 
soluble in water, the gases produced by it, such as the 
carbonic acid, the carburetted hydrogen, azote, and am- 
monia, furnish food for plants, or stimulants for their 
organs of digestion. It is not, however, well to prolong 
this decomposition too far ; for if it be completed, there 
will remain only some fixed salts, mixed with those earths 
and juices which have resisted its action. Besides, the 
effect of manures, which have been entirely decomposed, 
is almost momentary, lasting but for a single season ; 
whilst those which are employed before arriving at this 
state, continue to exert an influence for several years. In 
this last case, the decomposition, retarded by the separa- 
tion of the manures into small portions, continues to go 



NUTRITIVE MANURES. 51 

on gradually in the earth, and thus furnishes vegetation 
with its necessary aliments for a long time. 

The excrements of animals, formed by the digestion of 
their food, have already undergone a decomposition which 
has disorganized the principles of their aliments, and in a 
greater or less degree changed their nature. The strength 
of the digestive organs, which varies in each species of 
animal, the difference of food, and the mixture of the di- 
gestive fluids furnished by the stomach, modify these ma- 
nures to a very considerable extent. 

The excrements of some animals, as of pigeons, fowls, 
&c., are employed without undergoing any new fermenta- 
tion, because they consist mostly of salts, and contain but 
few juices. Fields are often manured with the excre- 
ments of sheep, collected in the sheep-folds, or scattered, 
as in parks, by the animals themselves upon the soil ; but 
in general the dung of horses and of horned cattle is made 
to undergo a new fermentation before being applied as 
manure. 

The most general method of producing the fermenta- 
tion of the dung of quadrupeds, is, in the first place, to 
form upon the ground of sheep-folds and stables a bed of 
straw O:- dry leaves. This bed is covered with the solid 
excrements of the quadrupeds, and impregnated with their 
urine. At the end of fifteen days or a month, it is carried 
to a place suited for fermentation, and there formed anew, 
care being taken every day to spread upon it litter and 
the scatterings of the racks. The formation of these 
beds, contributes much to the healthfulness of the stables 
and to the cleanliness of the animals. When, from a 
scarcity of straw, the beds cannot be made of sufficient 
thickness, or renewed often enough, a layer may be 
formed of lime or gravel, broken fine and covered with 
straw. These earths will imbibe the urine, and when 
they are penetrated by it may be carried into the fields to 
be buried in the soil. The nature of the earth, upon 
which beds are formed in sheep-folds or stables, should 
vary according to the character of the soil which is to 
receive them, because, by attention to this, the soil may 
be improved as well as manured. For argillaceous and 
compact earths, the layers should be formed of gravel 
and the remains of old lime mortars ; whilst those of fat 
marl or of clayey mud should be reserved for light and 
dry soils. 



62 CHYMISTRY APPLIED TO AGRICULTURE. 

In some countries, where good husbandry is much at- 
tended to, the floors of the stables are paved and slightly 
sloping, so that the urine flows off into a reservoir, where 
it is fermented with animal and vegetable substances, and 
used to water the fields at the moment when vegetation 
begins to be developed. 

The art of fermenting dungs with litter is still very in- 
complete in some parts of France. In one place they let 
it decay till the straw is completely decomposed ; in 
another they carry it into the fields as soon as it is taken 
from the stables. These two methods are equally faulty. 
By the first, nearly all the gases and nutritive juices are 
dissipated and lost; by the second, fermentation, which 
can take place only in masses, will be but very imperfectly 
carried on in the fields, and the rains can convey to the 
plants only that portion of the nourishment afforded by 
the manure, which they can obtain by a simple washing. 

The most useful art perhaps in agriculture, and that 
which requires the most care, is the preparation of dung- 
heaps. It requires the application of certain chymical 
principles, which it is not necessary for me to explain, 
since it is sufficient to point out to the agriculturist the 
rules by which he should be governed in his proceedmgs, 
without re juiring of him an extensive knowledge of the 
theory upon which they are founded. 

Solid substances, whether animal, vegetable, or mineral, 
do not enter into plants unless they are previously dis- 
solved in water, or are drawn in with that fluid in a state 
of extreme division. 

Animal and vegetable substances which are by their 
nature insoluble in water, may, by being decomposed, form 
new soluble compounds, capable of furnishing nourish- 
ment for plants. 

Animal and vegetable substances deprived by the ac- 
tion of water of their soluble particles, may, in the course 
of their decomposition, form new compounds susceptible 
of being dissolved. Of this I have given instances in 
speaking of mould. 

That which renders the art of employing dung-heaps 
difficult, in proportion as it is useful, is, that some meth- 
ods which are adopted occasion the loss of a part of the 
manure. In fact, when the clearings of the farm-yard are 
carried fresh into the fields, and applied immediately to 
the soil, vegetation is undoubtedly benefited by the salts 



NUTRITIVE MANURES. 53 

and the juices contained in them ; but the fibres, the fat- 
ness, the oils, remain inactive in the earth ; and their 
final decomposition is slow and imperfect. If, on the con- 
trary, the collections of the farm-yard be heaped up in a 
corner of it, the mass will speedily become heated, car- 
bonic acid gas will be evolved, and afterwards carburetted 
hydrogen, ammonia, azote, &c. A brown liquid, of which 
the color deepens gradually almost to black, moistens the 
heap, and flows upon the ground around it ; all is by de- 
grees disorganized ; and when the fermentation is com- 
pleted, there remains only a residue composed of earthy 
and saline substances, mixed with a portion of blackened 
fibre, and some carbon in powder. 

In those places where they do not allow fermentation 
to arrive to this degree of decomposition, they still lose, by 
mismanagement, a considerable part of their manure. 

The most common method is, to deposit in a corner of 
the farm-yard the dung and litter, as it is drawn from the 
stables, adding to the mass every time these are cleared, 
and allowing it to ferment till the period of sowing arrives, 
whether it be in spring or autumn, when it is carried 
upon the fields requiring it. 

This method presents many imperfections. In the first 
place, several successive layers being formed, no two of 
them can have undergone the same degree of fermenta- 
tion ; in some it will have gone on for six months, and in 
others but for fifteen days. In the second place, the heap, 
being exposed to rains, will, by frequent washings, have 
parted with nearly all its salts and soluble juices. In the 
third place, the extractive portions of the lower and cen- 
tral parts of the mass, the mucilage, the albumen, and 
the gelatine, will be entirely decomposed ; and, lastly, 
those gases which nourish plants, if developed at their 
roots, will have escaped into the air ; and Davy has ob- 
served, that, by directing these emanations beneath the 
roots of the turf in a garden, the vegetation was rendered 
very superior to that in the vicinity. 

How long should dunghills be allowed to ferment ; and 
what methods ought to be pursued in forming themt 
This question leads us to cast a glance upon the nature of 
dunghills ; and it is not till after having ascertained the 
difference amongst them, that it can be answered. 

The principal parts of vegetables which are employed 
5* 



54 * CHYMISTRY APPLIED TO AGRICULTURE. 

as manure contain mucilage, gelatine, oils, sugar, starch, 
extractive matter, and often albumen, acids, salts, &/C. 
with an abundance of fibrous matter, insoluble in water. 

The different substances afforded by animals, including 
all their excretions, are gelatine, fibrine, mucus, fat, albu- 
men, urea, uric and phosphoric acids, and some salts. 

The greatest part of the substances, constituting ani- 
mals and vegetables, are soluble in water ; and it is evi- 
dent that in that state they can be employed as manures 
without previous fermentation ; but it is necessary, that 
those which contain much insoluble matter should be 
decomposed by fermentation, because by that process their 
nature is changed, and they form new compounds, which, 
being capable of solution, can pass into the organs of 
plants. 

Messrs. Gay-Lussac and Thenard have obtained, by an 
analysis of the woody fibre, oxygen, hydrogen, and es- 
pecially more carbon, than from any other part of the 
plant, and they have determined their several proportions. 
We know that fermentation carries off much carbon ; it 
is then evident that, by causing the fermentation of the 
vegetable fibre, the principle which forms its distinguish- 
ing characteristic will be gradually diminished, and that 
it will no longer be a body insoluble in water. It is in 
this manner that woody plants and the driest leaves are 
converted into manure. 

But as all the solid parts of plants contain fibres which 
cannot be rendered soluble in water, but by a long period 
of fermentation ; and as it is in the fibre that carbon, a 
principle so necessary to vegetation, chiefly exists^ the 
fermentation of plants is indispensable to the procuring of 
the best part of their manure. 

The custom of appropriating some crops whilst green 
to the manuring of the ground, may perhaps be objected 
to ; but I have observed, that in that case the plants are 
buried in the earth at the time of flowering ; and whilst 
they are succulent, and their fibres soft, and but little 
formed ; and that warmth and the action of water in the 
earth was sufficient to decompose them : this would not 
take place if the stalks were dried and hardened by the 
formation of the grain. 

The dung of quadrupeds may be mixed advantageously 
with the earth at the time of being taken from the 
stable, if it contain no litter ; but if it does, it appears to 



NUTRITIVE MANURES. 55 

me better to cause it to undergo a slight fermentation, in 
order to dispose the straw or leaves of which it is com- 
posed to become manure. 

It is necessary, in producing the fermentation of dung 
and litter, to use certain precautions by which the incon- 
veniences arising from the usual mode may be avoided. 

Instead of heaping up in large masses the collections of 
the barn-yard and stables, and allowing them to rot un- 
covered, and exposed to the changes of weather, they 
should be placed under a shed, or be at least protected 
from the rain by a roof of straw or heath. Separate lay- 
ers should be formed of each clearing of the stables, 
cow-house, and sheep-pens. These layers should be from 
a foot and a half to two feet in thickness ; and when the 
heat, produced in them by fermentation, rises in the 
centre to more than 95°, or when the mass begfins to 
smoke, it should be turned, to prevent decomposition from 
going too far. 

Fermentation should be arrested as soon as the straw 
contained in the heap begins to turn brown, and its tex- 
ture to be decomposed. To do this, the mass may be 
spread, or carried into the fields, to be immediately mixed 
with the soil ; or there may be mixed with it mould, plas- 
ter, turf, sweepings, 6lc. 

When the dung is not of the usual consistency, as is 
the case with that of neat cattle during the spring and 
autumn, it ought to be employed immediately, as I have 
already stated ; but if it be impossible to apply it to the 
fields whilst recent, it should be mixed with earths or 
other dry and porous substances, which may serve as ma- 
nures for the fields destined to receive it. 

Upon nearly all our farms the dung of quadrupeds is 
exposed to the open air, without the protection of a shed, 
as soon as it is removed from the stables ; and is thus 
washed by the rains, which carry off all the salts, urine, 
and soluble juices, and form at the foot of the mass a 
rivulet of blackish fluid, which is either wholly evaporated 
or lost in the ground. In proportion as fermentation ad- 
vances, new soluble combinations are formed, so that all 
the nutritive and stimulating principles of the dung gradu- 
ally disappear, till there remain only some weak portions 
of the manure, intermingled with stalks of straw which 
have lost all their goodness. 

To remedy as much as possible an abuse so injurious 



56 CHYMISTRY APPLIED TO AGRICULTURE. 

to agriculture, it is necessary at least to dig a deep ditch 
to receive all the juices which flow from the dunghill, in 
order that they may be used in the spring upon the corn 
or grass lands ; or they may be preserved to water the 
grass lands with, after the first mowing. A large cask, 
fixed upon a small cart, and which can be filled by means 
of a hand pump, is sufficient for this purpose. Beneath 
the tap of the cask must be fitted a narrow chest about 
four feet long, with the bottom pierced with holes, through 
which the liquor may be scattered. This mode of water- 
ing, when used after mowing, produces wonderful effects 
upon the crop of the following year. 

Before deciding upon the question, whether dung and 
litter should or should not be made to ferment, it is neces- 
sary to take into consideration the nature of the soil to be 
manured. If this be compact, clayey, and cold, it is 
better that fermentation should not have taken place, as 
two effects will be produced by the application of the 
manure in an undecomposed state. In the first place it 
will improve the soil by softening and dividing it, so as to 
render it permeable by air and water ; and in the next 
place it will, whilst undergoing the successive processes 
of fermentation and decomposition, warm the soil. If, on 
the contrary, the soil be light, porous, calcareous, and 
warm, the thoroughly fermented manure, or shoi't 7nuck, 
as it is called by farmers, is preferable, because it gives 
out less heat, and instead of opening the earth, already 
too porous, to the filtrations of water, it moderates the 
flow of that fluid. Long experience has made these truths 
known to observing, practical farmers. 

When it is required to apply dung to any particular 
kind of soil, it is necessary that it should be used accord- 
ing to a knowledge of its qualities. The dung of animals 
bearing wool is the warmest; next, that of horses; whilst 
that of cows and oxen contains the least heat of any. 

Soft or fluid animal substances change the most easily ; 
and the progress of their decomposition is rapid in pro- 
portion to the diminution of the quantity of earthy salts 
contained in them. Their decomposition produces an 
abundance of ammonial gas. This circumstance distin- 
guishes them from vegetable substances, the decomposition 
of which gives rise to the production of that gas, only as 
far as they contain a small portion of albumen. It is par- 
ticularly to the developement of ammonial gas, which. 



NUTRITIVE MANURES. 57 

combined with gelatine, passes into plants, that we can 
attribute the wonderful effect produced upon vegetation 
by certain dry animal substances, of which we shall speak 
presently. 

Next to the dung of animals, of which I have just 
spoken, the urine of horned cattle and of horses is the 
most abundant manure which can be used in agriculture ; 
and it is not without regret that I see every day so little 
pains taken to collect it. I have already observed, that 
in those countries where agriculture is conducted with the 
most care and skill, all the stables are floored, and the 
bottoms of them gently sloping, so as to conduct all the 
urine into a reservoir, where the remains of rape-seed, 
flax, wild cabbage, human excrements, &.c. &lc. are thrown 
into it to undergo fermentation. In the spring, when 
vegetation begins to be developed, this fermented liquor 
is carried into the fields to water the crops. 

There are few animal substances of which the nature 
varies as much as that of urine; the quality of food, or 
the state of health, produces a sensible change in it. 
The urine of animals is more or less abundant and active 
in its qualities, in proportion as their food is juicy or dry. 
Those which live upon dry fodder give less urine than 
those which are fed upon green herbage ; but that of the 
first contains a greater quantity of salts than that of the 
last; and that which is produced directly by drink, con- 
tains less animal matter than that which is secreted from 
the blood by the urinary organs. There are different 
states of individuals, which may explain satisfactorily the 
disagreements in the results which have been given, by 
the numerous analyses which have been made of this 
fluid. 

Mr. Brandt has found the urine of a cow to contain. 

Water 65 

Phosphate of lime 5 

Muriate of potash and of ammonia . . 15 

Sulphate of potash 6 

Carbonate of potash and of ammonia . 4 
Urea 5 



100 

Messrs. Fourcroy and Vauquelin have extracted from 
that of the horse, 



58 CHYMISTRY APPLIED TO AGRICULTURE. 

Carbonate of lime . . . . 11 
Carbonate of potash .... 9 

Benzoate of soda 24 

Muriate of potash .... 9 

Urea 7 

Water and mucilage .... 940 

1,000 

An analysis of human urine by M. Berzelius afforded. 

Water 933 

Urea 30.1 

Uric acid 1 

Muriate of ammonia, free lactic acid, 

lactate of ammonia, and animal matter 17.4 

981.5 

The remainder is composed of sulphates, phosphates, 
and muriates. 

It may be seen from these analyses, that there is a wide 
difference in the urine of various animals, but that all con- 
tain salts which enter into plants, with the water by which 
they are held in solution ; and draw in at the same 
time those animal portions, which, like urea, are easily 
soluble, and can be decomposed without difficulty. 

Amongst the principles contained in urine, there are 
some salts undecomposable by the digestive organs of 
vegetables ; such are the phosphate of lime, the muriate 
and the sulphate of potash. These can serve only to ex- 
cite and stimulate the organs ; but the urea, the mucilage, 
the uric acid, and other animal matters, must be con- 
sidered as eminently nutritive. Urine in its recent state 
should never be employed as manure ; it acts with too 
much force, and has a tendency to dry the plants ; it 
should therefore be either mixed with water, or allowed to 
ferment. 

Urine is very useful for moistening all those substances 
which enter into composts ; it increases the fertilizing 
properties of each one of them, and facilitates the fermen- 
tation of those which need to be decomposed before yield- 
ing their nutritive qualities. 

Urine, when combined with plaster, lime, &c., forms a 
very active manure for cold lands. 

Bones have, at the present time, become, in the hands 
of the agriculturist, a powerful agent in fertilizing the soih 



NUTRITIVE MANURES. 59 

These parts of animals are principally composed of phos^ 
phate of lime and of gelatine. Those bones which are 
most usually employed, contain about equal quantities of 
phosphate and gelatine. The bones of the ox yield from 
fifty to fifty-five per cent, of gelatine ; those of the horse 
from thirty-six to forty ; and those of the hog from forty- 
eight to fifty. 

The bones of young animals contain more gelatine than 
those of older animals, and have a less compact texture. 
The bones of the feet of the elk, the roe-buck, stag, and 
hare afford, upon analysis, from eighty to ninety per cent, 
of phosphate. 

When bones are to be employed as a manure, they 
should be ground fine, and thrown into a heap to ferment. 
As soon as this action shall have commenced, so as to 
give out a penetrating odor, the mass should be spread 
upon the earth, and be afterwards mixed with it; or it 
may be thrown upon the seed, and buried in the ground 
with it. When seeds are sown in furrows, it is a good 
method to place some of the ground bones in the furrows 
with them. 

In some countries the fat and a great part of the gela- 
tine are extracted from bones, by boiling them in water, 
before selling them for agricultural purposes. But by this 
operation they are deprived of a great part of their fertil- 
izing powers. Upon carefully observing the appearance 
of a mass of bones under fermentation, I found the sur- 
face of a part of them to be covered with a thin coating 
of an unctuous substance, sharp and biting to the taste. 
This appeared to me to be formed by the combination of 
gelatine with ammonia ; this last being always developed 
during the decomposition of all animal substances. The 
observations of M. D'Arcet, to whom we are indebted for 
a very valuable work upon gelatine, support this opinion. 

It is possible, that, when the ground bones are em- 
ployed without having been first submitted to the com- 
mencement of a fermentation, the gelatine is gradually 
decomposed in the ground, and the same result at length 
produced ; or, we can conceive that water, acting upon 
the bones, will dissolve the gelatine, and transmit it to 
plants ; and in both these cases the influence of the bones 
upon vegetation is very great, whether it be considered 
as a purely nutritive manure, or in the double connexion 
of a nutritive and stimulating substance. 



60 CttVMISTRY APPLIED TO AGRICULTURE. 

When bones are calcined in a close vessel, they yield 
oil and carbonate of ammonia ; the proportion of the 
phosphate is not sensibly diminished ; but the gelatine is 
decomposed. There remains after the operation from six- 
ty-six to seventy-two per cent, of the weight of the bones 
employed. This residue, broken and pulverized with care, 
is of great use in the process of refining sugar. After 
having been used in this process, and become impreg- 
nated with ox-blood and animal carbon, I have found it 
to be one of the best manures which I could employ for 
trefoil and clover. It should be scattered with the hand 
upon the plants, when vegetation begins to be developed 
in the spring. 

Some of the dry parts of animals, as the horns, hoofs, 
and claws, approach closely to bones in the nature of their 
constituent principles ; but the proportions of these va- 
ry prodigiously. In such parts, gelatine constitutes the 
largest portion ; and for this reason they are more es- 
teemed as manure than the bones. M. Merat-Guillot has 
found but twenty-seven per cent, of phosphate of lime in 
the horn of a stag, and M. Hatchett, by an analysis of 
five hundred grains of the horn of an ox, gained only one 
fifth part of earthy residuum, of which a little less than 
one half was phosphate of lime. 

The clippings and parings of horns form an excellent 
manure, of which the effect is prolonged during a suc- 
cession of years, owing to the difficulty with which water 
penetrates them, and the little tendency they have to fer- 
ment. 

A very good manure is likewise formed from wool. Ac- 
cording to the ingenious experiments of M. Hatchett, hair, 
feathers, and wool are only particular combinations of gela- 
tine with a substance analogous to albumen ; water can 
only dissolve them by means of fermentation, which takes 
place slowly, and after a long time. 

One of the most surprising instances of fertile vegeta- 
tion that I have ever seen, is that of a field in the neigh- 
bourhood of Montpellier, belonging to a manufacturer of 
woollen blankets. The owner of this land causes it to be 
dressed every year with the sweepings of his work-shops ; 
and the harvests of corn and fodder which it produces, 
are astonishing. 

It is well known, that the hairs of wool transpire a fluid 
which hardens upon their surface, but which possesses 



NUTRITIVE MANURES. 61 

the property of being easily soluble in water. This sub- 
stance has received the name of animal sweat ; the water 
in which wool has been washed contains so much of it, as 
to make it very valuable as a manure. 

I saw, thirty years since, a wool merchant in Montpel- 
lier, who had placed his wash-house for wool in the midst 
of a field, a great part of which he had transformed into 
a garden. In watering his vegetables he had used no 
other water than that of the washings; and the beauty 
of his productions was so great, as to render his garden 
a place of general resort. The Genoese collect with care, 
in the south of France, all they can find of shreds and 
rags of woollen fabrics, to place at the foot of their olive 
trees. 

According to the analysis of M. Vauquelin, this animal 
sweat is a soapy substance, consisting of a base of potash, 
with an excess of oily matter, and containing, besides, 
some acetate of potash, a little of the carbonate and of 
the muriate of the same base, and a scented animal 
matter. 

The dung of birds is another very valuable manure ; 
differing from that of quaf^rupeds in the food's being better 
digested; in containing more animal matter, being richer 
in salts, and affording some of the principles which are 
found in the urine of four-footed animals. 

The dung of those sea-fowls, which are so numerous in 
the islands of the Pacific ocean, and of which the excre- 
ment furnishes an important article of commerce with 
South America, as, according to the accounts of M. Hum- 
boldt, they import into Peru fifty shiploads of it annually, 
contains, besides a great quantity of uric acid partly satu- 
rated by ammonia and potash, some phosphate of lime, of 
ammonia, and of potash, as well as some oily matter. 
Davy found the dung of a cormorant to contain some uric 
acid. 

The good effects resulting from the use of pigeons' 
dung, in our country, has caused it to be carefully collected. 
One hundred parts of this, when fresh, yielded to Davy 
twenty-five parts of matter soluble in water, whilst the same, 
after having undergone putrefaction, gave but eight ; 
whence this able chymist concluded, with reason, that it 
was necessary to employ it before being fermented. This 
is a warm manure, and may be scattered by the hand 
6 



6@ CIJYMISTRY APPLIED TO AGRICULTURE. 

before covering the seed ; or it may be used in the spring 
upon strong lands, when vegetation appears languid. 

The excrement of the domestic fowl approaches nearly 
in its qualities to that of the pigeon, without, however, pos- 
sessing the same degree of power. It contains also some 
uric acid, and may be applied to the same purposes as 
pigeons' dung. 

In the south of France, where they raise many silk- 
worms, they make great use of the larvas, after the silk 
has been spun from the cocoons. They are spread at the 
foot of the mulberry and other trees, of which the vegeta- 
tion is in a languishing condition ; and this small quantity 
of manure reanimates them surprisingly. Upon distilling 
some of these larvas, I found more ammonia than I have 
ever met with in any other animal matter. 

Night soil forms an excellent manure ; but farmers 
allow it to be wasted, because it is too active to be em- 
ployed in its natural state, and they know not how either 
to moderate its action, or to appropriate it during different 
stages of fermentation to the wants of various kinds of 
plants. 

In Belgium., which has been the cradle of enlightened 
agriculture, and where good modes of cultivation are con- 
tinued and constantly improved, thev make astonishing 
use of this kind of manure. The first year of its decom- 
position, they cultivate upon the soil to which it is ap- 
plied, oleaginous plants, such as hemp and ftax ; and the 
second year sow the land with corn. They likewise mix 
water with urine, and use it to water the fields in the 
spring, when vegetation begins to unfold. This substance 
is likewise dried and scattered upon fields of cabbage. 

The Flemings value this kind of manure so much, that 
the cities set a high rate upon the privilege of disposing 
of the cleansings of their privies ; and there are, in each 
one of them, sworn officers for the assistance of those who 
wish to make purchases. These officers know the degree 
of fermentation suited to each kind of plant, and to the dif- 
ferent periods of vegetation. 

We shall find great difficulty in bringing this branch of 
industry to the same degree of perfection amongst us, that 
it has arrived at in Belgium, because our farmers do not 
realize its importance, and have a repugnance to employ- 
ing this kind of manure. But, could they not collect care- 
fully all these matters, mix them with lime, plaster, or 



NUTRITIVE MANURES. 63 

gravel, till the odor was dispelled, and then carry the 
whole upon the fields ? 

Already, in most of our great cities, the contents of the 
privies are used for forming poudrette: this pulverulent 
product is sought for by our agriculturists, who acknowl- 
edge its good effects ; let us hope, that, becoming more 
enlightened, they will employ the fecal matter itself, as 
being more rich in nutritive principles, and abounding 
equally in salts ; they can easily govern and moderate the 
too powerful action of this, by fermentation, or what is still 
better, by mixing with it plaster, earth, and other absorb- 
ents, to correct the odor. 

As dunghills are the riches of the fields, a good agri- 
culturist will neglect no means of forming them ; it ought 
to be his first and daily care, for without dung there is no 
harvest. The scarcity of dunghills, or what is the same 
thing, the bad state of the crops, sufficiently proves the pre- 
judices, by which the peasant is everywhere governed, and 
the habitual blindness with which he proceeds in his labors. 
In our country, many of those who cultivate the land, 
know only the kinds of straw which are suitable for fur- 
nishing manure, and in a dunghill of litter, consider them 
as acting- the principal part, whereas they are only feeble 
accessories. 

According to the experiments of Davy, the straw of bar- 
ley contains only two per cent, of substance soluble in water, 
and having a slight resemblance to mucilage ; the remainder 
consists entirely of fibre, which can be decomposed only 
after a long time, and under circumstances calculated to 
facilitate the operation. 

I do not believe that there is in the whole vegetable 
kingdom, an aliment afford ino- so little nutriment, either for 
plants or animals, as the dry straw of grain ; serving only 
to fill the stomachs of the latter, and furnishing to the 
former but about one hundredth part of its weight of solu- 
ble manure. 

Weeds, leaves of trees, and all the succulent plants 
which grow so abundantly in ditches and waste lands, 
under hedges, and by the road side, if cut or pulled when 
in flower, and slightly fermented, furnish from twenty to 
twenty-five times more manure than straw does. These 
plants, carefully collected, furnish to the agriculturist an 
immense resource for enriching his lands. Besides the 
advantage arising from the manure furnished by these 



64 CHYMISTRY APPLIED TO AGRICULTURE. 

plants, the agriculturist will find his account in prevent- 
ing the dissemination of their seeds, which, by propagat- 
ing in the fields, deprive the crops of the nourishment of 
the soil. The turf, that borders fields and highways, may 
be made to answer the same purpose, by cutting it up with 
all the roots and the earth adhering to them, rotting the 
whole in a heap, and afterwards carrying the mass upon 
the fields, or what is still better, by burning it, and dress- 
ing the land with the products of the combustion. 

If straw did not serve as beds for animals, and did not 
contribute, at the same time, to their health and cleanliness, 
it would be better to cut the ears of corn and leave the 
stalks in the fields ; since they serve only as absorbents of 
the true manures. 

It is always said that barn-yard manure, besides its nu- 
tritive virtues, possesses the advantage of softening hard 
lands, and rendering them permeable by air and water. I 
do not deny the truth of this ; I even acknowledge that it 
owes this property almost entirely to the straw which it con- 
tains ; but the same effect would be produced by burying 
the straw upon the spot. 

Besides the characteristic of providing plants with food, 
the various kinds of dung possess other qualities, which 
add to their fertilizing powers. Dung, as it is applied to 
the ground, is never so much decomposed as to have ceased 
fermenting ; and from the moment it is mixed with the 
soil it produces in it a degree of warmth favorable to vege- 
tation, and serving to guard the young plants against the 
effects of those sudden returns of cold in the atmospheric 
temperature, which are so often experienced. On account 
of the viscous fluids which it contains, dung is not easily 
dried, unless it be in contact with the air. It therefore 
preserves the roots of the plants in a state of moisture; 
and supports vegetation at those periods, when, without it, 
plants would perish from drought. It likewise contains 
many salts which are transmitted by water to plants, serv- 
ing to animate and excite their functions. The various 
kinds of dung, mixed with earth, may be considered in 
the light of amendments to the soil ; and in this view they 
ought to vary according to the nature of the earth to be 
improved. Compact soils require to be separated and 
warmed ; they require, then, those manures which have 
been but slightly fermented, and that are the richest in 
salts. Calcareous and light earths require oily manures, 



NUTRITIVE MANURES. 65 

Xvhich decompose slowly, and can retain water for a long 
time, to furnish it to the wants of plants in seasons of 
drought. 

It is by separating these principles, that we may be able 
to appropriate the various kinds of manure to each species 
of soil and plant : the attention of agriculturists is already 
directed, upon this point, to the composition of mixtures 
of manures, called composts. These are formed by ar- 
ranging, one above another, beds of different kinds of 
manure, taking care to correct the faults of one by the 
properties of another, in such a manner as to produce a 
mixture suited to the soil to be enriched by it. 

For example, if it be required to form a compost for a 
clayey and compact soil ; the first bed must be made of 
plaster, gravel, or mortar rubbish ; the second, of the lit- 
ter and excrements of horses, or sheep ; the third, of the 
sweepings of yards, paths, and barns, of lean marl, dry 
and calcareous ; of mud deposited by rivers, of the fecal 
matter collected upon the farm, the remains of hay, straw, 
etc., and this in its turn must be covered with a laying of 
the same materials as the first. Fermentation will take 
place first in the beds of dung, and the liquor flowing from 
these will mingle with the materials of the other layers; 
when the mass exhibits the signs which I have pointed 
out, as indicating decomposition to be sufficiently ad- 
vanced, it must be carried into the fields, care being first 
taken to mix well the substances composing the different 
layers. 

If the compost be designed to manure a light, porous, 
and calcareous soil, it must be formed of materials of a 
very different character. In this case it is necessary that 
argillaceous principles should prevail ; the substances must 
be compact, the dung of the least heating kind, and the 
fermentation continued, till the materials form a yielding 
and glutinous paste; the earths must be clayey, half baked, 
and pounded, or consisting of fat and argillaceous marl, 
and mud from the sea coast. Of these all the layers must 
be formed. 

By following these principles in ray operations, I have 
completely changed the nature of an ungrateful soil in the 
neighbourhood of one of my manufactories. Over this soil, 
composed of calcareous earth and light sand, I spread, 
during several years, some calcined clayey earth ; and this 
land, upon which I could formerly raise only stone fruit, 
6* 



66 CHVMISTRY APPLIED TO AGRICULTURE. 

has become adapted to fruit containing kernels ; and pro- 
duces excellent wheat, whereas before it bore only scanty 
crops of oats and rye. 



ARTICLE II. 

Of Stimulating Manures. 

I HAVE hitherto spoken only of those manures which 
contain, at the same time with aliments necessary for 
vegetation, the salts which are inseparable from them j 
and which pass, in a state of solution, into the organs of 
plants to stimulate their action. I shall now speak particu- 
larly of these salts, explaining in what manner they act, 
and how their utility in vegetable economy differs materially 
from that of the alimentary principles ; and showing that 
they can often be so employed as to increase the activity of 
vegetation. 

It appears from the results of the critical experiments 
which M. Saussure has made upon these substances, that 
the salts and extracts, when dissolved in water, are absorbed 
by the roots of plants. 

The absorption of hurtful salts is easy and abundant, in 
proportion as the plant is languishing, sickly, or mutilated. 
From this principle, established by experiments, it follows 
that the absorption of fluids and salts by the plants is not 
a passive and purely physical faculty ; but one, which is 
determined by those laws of vitality, vv^hich govern the 
plant during life. It is only when the power of these laws 
is weakened by a sick or languishing state of the plant, 
that external agents can act upon it in an absolute manner. 
Plants do not draw in indifferently, or in the same quan- 
tities, all substances which can be held in solution by wa- 
ter ; they absorb, from preference, those which are least 
viscid. 

From the preceding statements it is rational to conclude, 
that plants do not maintain a strictly passive state in regard 
to their aliments ; but that to a certain degree they have a 
preference, and taste, respecting them; and that the physi- 
cal laws predominate, to the injury of the vital organization, 
in proportion to the sickly or languishing condition of the 
plant. 



STIMULAI^ING MANURES. 67 

All the soft and fibrous portions of plants, are evidently 
the product of the elaboration carried in their organs, of 
the juices and gases by which they are nourished. The 
saline particles, which plants contain, are unchanged, and 
such as are furnished by the soil. 

Whatever may be the variety of products presented to 
us by the vegetable kingdom, the elements which compose 
them are few in number. They contain only oxygen, car- 
bon, hydrogen, and azote, combined in an immense variety 
of proportions ; some hundredths more or less, in the propor- 
tions of these constituent principles, often cause an aston- 
ishing difference in the character of their products. It is 
this which occasions the slightest alteration produced in the 
organs to give rise to new compounds, bearing no resem- 
blance to the first. 

No one has ever disputed that the juices, the oils, the 
resins, the fibre, and other essential parts of vegetation, 
are the result of the action of the different organs of 
plants ; and that the elements composing them were those 
of the bodies by which they are nourished, and which 
each combines in a manner peculiar to itself, and fitted to 
its own organization. There is, in all this, nothing like 
creation, but simply decomposition upon one side, and, upon 
the other, a new combination of the elements, in different 
proportions. 

Many philosophers, in other instances very correct, have 
asserted that plants themselves form, even by the act of vege- 
tation, salts and earths ; but, as science has advanced, it 
has been ascertained that none of the experiments cited by 
them have been made with exactness. Some have watered 
plants with distilled water ; others have raised them in 
washed sand ; nearly all have allowed free access of the 
air to them ; many have analyzed, with a certain degree 
of care, the soil upon which they raised their plants ; and 
nearly all have concluded, that the salts and earths which 
they found in them, and of which they could demonstrate 
neither the existence, nor even the quantity if found, in 
the different substances concurring to produce vegetation, 
must be the work of the plant. But does not the often 
disturbed atmosphere frequently change the salts, and the 
earths, which it deposits upon plants? Does not the dust 
which it carries, alight upon the upper surfaces of leaves 
and branches 1 Water, the best distilled, according to the 



68 CHYMISTRY APPLIED TO AGRICULTURI5. 

experiments of Davy, contains some alkaline and earthy 
atoms. 

Messrs. Schrader and Braconnot have published the re- 
sults of their experiments, by which they have been led to 
believe, that salts and earths are created in the organs of 
plants ; but M. Lassaigne has proved, that the salts and 
earths, contained in the developed plant, are the same as 
those that are found in the seed from which they sprang. 

M. Th. de Saussure, whose opinion upon these matters 
, is of great weight, has proved that plants do not create any 
of these substances. 

Besides, if the formation of certain salts be a power of 
the plant itself, why does not the salsola afford more ma- 
rine salt when it grows at a distance from the sea? Why, 
under the same circumstances, does not the ^' tamarisk" 
furnish more sulphate of soda? and, finally, why does the 
turnsol remain destitute of salt-petre, if raised upon a soil 
which does not contain it? 

Be this doctrine as it may, there are two practical truths 
which we do know ; the first is, that certain sahs enter, 
if I may so speak, as natural elements into the composition 
of some plants ; since it is found that they languish 
in earths not containing those substances; and that the 
plants absorb them abundantly, when they are present. 
The second is, that the salts ought always to be united with 
manures ; the excellence of which is increased, in propor- 
tion to the quantity they contain, provided it do not exceed 
the wants of the plants, and that the action be not too 
energetic. 

I may add, that a plant absorbs, from preference, the 
salt most analogous to its nature. The salsola, which 
grows by the side of the tamarisk, sucks up from the earth 
marine salt ; whilst the tamarisk imbibes from it the sul- 
phate of soda. It is proved by the analysis of plants of 
different kinds, that have been raised upon the same 
ground, that they do not furnish the same salts, or that, at 
least, they present a great difference in the quantities they 
contain. 

The salts are necessary to plants ; they facilitate the ac- 
tion of their organs so much, that they are often employed 
without mixture. 

Limestone submitted to the action of fire loses the car- 
bonic acid, which is one of its constituent principles, and 



STIMULATING MANURES. 69 

the result is a whitish stone, opaque and sonorous, of a 
sharp and burning taste, absorbing water with noise and 
heat, and forming with it a paste, which is a perfect hydrate. 
Good iitnestone may be deprived of 50 per cent, of its 
weight by calcination, but it is seldom that the heat of the 
kilns is sufficient to deprive it of more than from 35 to 40 
per cent, when the carbonate is dry. 

As soon as lime is exposed to the air, it absorbs moisture 
from it with great readiness ; gradually cracking and break- 
ing in pieces. It likewise absorbs the carbonic acid con- 
tained in the atmosphere, and is thus insensibly reduced to 
an impalpable powder. 

In this manner, lime resumes the principles of which it 
had been deprived by calcination, and is reconstituted lime- 
stone, or calcareous carbonate, without regaining its solidity. 
In proportion as the recomposition goes on, the lime loses 
the properties which it had acquired from the action of 
fire ; it ceases to be caustic, its solubility in water is di- 
minished, and its affinity for that fluid becomes almost 
nothinor. 

The lime used in agriculture is that which has been 
slacked by air. Unslacked lime destroys vegetation, at 
least if it be not combined with manures which moderate 
its action, or with such bodies as can furnish enough car- 
bonic acid to saturate it. 

We are indebted to Davy for some experiments which 
throw a great light upon the action of lime upon vegetation. 
He has proved that the fibrous portion of plants, deprived 
of all the particles which can be dissolved by water*, presents 
another series, soluble after having been for some time 
macerated with lime. Thus lime may be very efficaciously 
employed, when it is wished to convert dry wood or fibrous 
roots, and stalks, to the nourishment of plants. Limestone 
broken, and lime completely restored to the state of a 
carbonate, do not produce this effect ; it is necessary 
to employ lime slacked with water, and mixed with a fresh 
portion of that fluid, and the fibrous substances must remain 
for some time exposed to the action of this solution. In 
the case of which I have just spoken, the lime renders sol- 
uble and suited to the nourishment of plants, some sub- 
stances, which, in their natural state, do not possess this 
characteristic ; and for this purpose the use of it may be 
very advantageous. Thus, when it is desirable to convert 
ligneous and fibrous plants into manure, it may be done by 
treatinor them with lime. 



70 CHYMISTRY APPLIED TO AGRICULTURE. 

If it be required to employ, as manure, some substances, 
whether animal or vegetable, which are by nature soluble 
in water, their mixture with lime forms new compounds of 
natures completely different from their constituent principles, 
but which may, in time, become very proper for the nutri- 
ment of plants : this requires some explanation. 

The compounds formed by lime with nearly all the soft 
animal or vegetable substances which will combine with 
it, are insoluble in water ; accordingly, lime destroys or 
greatly diminishes the property of fermentation in the 
larger part of them ; but these same compounds at length 
undergo a change from being exposed for a length of time to 
the constant action of air and water ; the lime passing to the 
state of a carbonate, and the animal and vegetable substances 
being gradually decomposed, and furnishing new products 
capable of supplying nourishment to plants ; so that lime 
answers two great purposes for nutriment ; first, it disposes 
certain insoluble bodies to form by their decomposition solu- 
ble compounds ; and, secondly, it prolongs the action and 
nutritive virtue of some soft and insoluble animal and vege- 
table substances, beyond the term they would continue to 
act if they were not made to enter into combination with 
lime. 

Very striking instances of the facts which I have just 
stated, may be found in some of the operations performed 
in various branches of manufactures. For instance, in 
the process of refining sugars to free them from the vege- 
table extract and the albumen which they contain, the milk 
of lime is employed, which, combining with these sub- 
stances, rises to the surface of the liquid in the form of a 
thick and insoluble foam or scum ; this, if carried immedi- 
ately into the fields, destroys vegetation, but if deposited in a 
ditch during a year, it forms one of the most fertilizing 
manures with which I am acquainted. I have established 
this fact by having employed, in this manner, during the 
period of a dozen years, the abundant foam arising from the 
first operations performed upon the sugar of beets in my 
manufactory. 

From the explanation which I have given of the manner 
in which lime acts, we may draw some conclusions in regard 
to its uses, and to the manner in which it should be em- 
ployed in order to have the results, arising from its applica- 
tion, conform to those which have been produced by en-, 
lightened experiments. 



STIMULATING MANURES. 71 

It is acknowledged that lime is principally useful upon 
fallow lands which are broken up ; upon grass lands, 
whether natural or artificial, which are prepared for culti- 
vation ; and upon muddy lands, which are to be put into 
a state fit for culture. It is well known, that in all these 
cases there exists in the land a greater or less quantity of 
roots, which, by the application of lime, may be made to 
serve more immediately for manure, by the solubility it 
will give to the new products formed by them ; but this 
effect can be produced neither by spreading the lime on 
the land at the time of sowing the seed, nor by throwing 
it «pon the soil without covering it, nor by sprinkling it 
upon the plants which have begun to unfold ; it is neces- 
sary to scatter it upon the land before the first tilling, and 
only as fast as it can be mixed with the soil, as lime loses 
its strength by exposure to the air. Subsequent tillages 
mix it more intimately with the soil, and place it in con- 
tact with the roots and stalks upon which it is to act, and 
at the end of some months this action is completed. 

Independently of this effect, which, in my opinion, is 
the most important, lime exercises other powers, which 
make it a very valuable agent in agriculture. It cannot 
be denied, that the long existence and the barrenness of 
a marshy or turfy soil, give rise in such lands to myriads 
of insects, which repeated tillages, and frequent changes 
of crops, can destroy only in a great length of time; whilst 
the mixture of lime with the earth performs the u'ork im- 
mediately. It is certain, that some plants which injure 
the soil and the crops, escape every tilling ; but are imme- 
diately destroyed by the action of lime. It is clear, that 
to produce these effects, the lime must be applied in the 
caustic state ; the mode of preparing it is as follows. 

As lime absorbs water with avidity, exhaling vapor and 
producing noise and heat, and crumbling into pieces, that 
liquid may be thrown upon it, till the whole mass is re- 
duced to a dry and impalpable powder ; and it is in this 
state that it must be used. 

In order to preserve the husbandman from the delete- 
rious effects upon the lungs, of this light powder, it is best 
to mix it with some moistened earth ; and in order that it 
may preserve all its virtue, it is necessary that it should be 
immediately buried in the soil by ploughing. 

The custom of employing air-slacked lime, which is 
lime in the state of a sub-carbonate, is spreading in France 



t/J CHEMISTRY APi»LIED TO AGKlCULTtJllfeV 

every year, and is productive of good results. This lim^ 
is, undoubtedly, less active than that which has been 
slacked by water; but it requires fewer precautions in the 
use of it, and is not liable to so many inconveniences. 

When lime has been acted upon by the air, till it is 
reduced to the state of an impalpable powder, it is used 
with great advantage by mixing it with dunghill manure j 
it serves to correct the acidity arising from the decompo- 
sition of certain portions of this, such as the mash of 
•grapes, 6lc. &c., and it absorbs the juices that would flow 
off and be lost, or would be too rapidly decomposed ; it 
likewise fixes the gases, which would otherwise ascend 
into the atmosphere. This mixture spread upon the fields 
excites vegetation, warms cold soils, divides those which 
are compact, regulates the fermentation of manures, and 
furnishes to plants, gradually, and in proportion to their 
Wants, the nutritive principles with which it is impreg 
nated. 

Lime slacked by air does not entirely lose the property 
of being soluble in water, and when used it is carried into 
the organs of plants by that liquid, producing those good 
effects which arise from the employment of saline sub- 
stances, in small quantities. 

Limestone saturated with carbonic acid, though it may 
be reduced to powder, does not produce any of the good 
effects arising from the use of quick-lime, or of that which 
has been slacked by air. Its almost sole use is to divide 
compact earths, to facilitate the passage of water through 
them ; and to dispose them to yield more readily to tillage. 

Limestone often contains some magrnesia, which exer- 
cises a singular power in modifying the action of the lime. 
M. Tennant obtained from 20 to 22 per cent, of magnesia 
from limestone, in which the lime was in the proportion of 
only from 29 to 31 per cent., by throwing upon this mix- 
ture a little more nitric acid, diluted with water, than was 
necessary to saturate it ; the liquor remained turbid, and 
of a whitish color. 

I have always observed that all earths, of whatever 
nature, containing magnesia, render the waters covering 
them whitish; and that the agitation of these waters by 
the wind takes from them all their transparency. When 
such waters form ponds or pools, they are called white 
waters. 



STIMULATING MANURES. 73 

Magnesian earths possess but little fertility ; and when 
the lime employed for agricultural purposes contains mag- 
nesia, its beneficial effects do not follow. In order to ac- 
count for this difference of action, it is necessary to take 
into consideration, that magnesia has less affinity for car- 
bonic acid than lime has, and that, consequently, when 
the two earths are mingled together, the magnesia pre- 
serves its causticity, even when the lime is saturated with 
carbonic acid, and brought back to the state of lime-stone. 
Thus it appears that magnesia can preserve its caustic 
properties, and exercise its deleterious effects upon vege- 
tation, during a long time. 

The use of plaster, or gypsum, which has become com- 
mon in Europe as a manure, is one of the most important 
improvements that has ever been made in agriculture. It 
has even been introduced into America, where it was 
made known by Franklin upon his return from Paris. 
As this celebrated philosopher wished that the effects of 
this manure should strike the gaze of all cultivators, he 
wrote in great letters, formed by the use of the ground plas- 
ter, in a field of clover lying upon the great road to Wash- 
ington, *' This has been plastered," The prodigious vege- 
tation which was developed in the plastered portion led 
him to adopt this method. Volumes upon the excel- 
lences of plaster would not have produced so speedy a revo- 
lution. From that period the Americans have imported 
great quantities of plaster of Paris. 

There are, however, some tracts of country where the 
use of plaster has been attempted without success. But 
this arose from its being one of the original constituents 
of the soil, which derived no advantage from the addition 
of a new quantity. The existence of this salt, naturally, 
in those lands upon which plaster produced little or no 
effect, has been proved by analysis. 

Gypsum is a compound of sulphuric acid and lime, con- 
taining more or less of the water of crystallization. A 
moderate heat deprives it of its water of crystallization, 
and renders it opaque. It can then be reduced to powder, 
and employed in that state. Though the prepared gyp- 
sum absorbs water with avidity, and its consistency is 
affected by the mixture, it may be preserved many months 
without its properties being sensibly affected. Nothing 
more is necessary for this purpose than to head it up in 
tight casks. 

7 



74 CHYMISTRY APPLIED TO AGRICULTURE. 

Gypsum carefully broken is likewise much used ; and 
there are some farmers who attribute to it the same effica- 
cy as is possessed by that prepared by heat. I have my- 
self made some comparative experiments, and observed, 
that the baked plaster evidently produced a little more 
effect the first year, but during the three years which fol- 
lowed, the difference was almost nothing. 

The gypsum is scattered by the hand at the time when 
the leaves of the plants begin to cover the ground, and it 
is best to take advantage of a light rain for the operation, as 
it is thought to be beneficial to have the leaves moistened, 
in order that they may retain a small portion of the 
powder. 

The effect of the gypsum is perceptible during three or 
four years. The use of it can be resumed at the end of 
that time. The quantity in which it is usually employed 
is from 2f cwt. to 3} cwt. per acre. 

Much has been said upon the effects of plaster. Some 
have pretended that its action ought to be attributed to 
the force with which it absorbs water. But it solidifies 
that liquid, and does not part with it either to the atmo- 
sphere, or to any other surrounding body ; so that thi«5 
doctrine does not appear well founded. Besides, if its 
action were from this cause, it would be momentary, 
and would cease after the first rains ; and this is con- 
tradicted by experience. Moreover, it is believed that 
the broken gypsum has not the property of absorbing 
water ; and yet it produces nearly the same effects as the 
baked and powdered plaster. 

Others have thought that plaster acted only by favoring 
the putrefaction of animal substances and the decompo- 
sition of manures. But Davy has refuted this opinion by 
direct experiment, placing it beyond a doubt, that the 
mixture of plaster with manures, whether animal or vege- 
table, does not facilitate decomposition. 

There are others, again, who attribute the effects of 
plaster to its stimulating properties ; and these adopt, in 
its utmost extent, the opinion which I have formed upon 
the subject. It still remains, however, to be explained, 
why this salt, which is not more stimulating than many 
others, acts with so much better effect, and why its action 
is continued during several years, whilst that of others is 
exhausted in so much less time ; whv this salt never dries 
plants, whilst the others, if employed in excess, burn them 
up and destroy them. These are problems which remain 



STIMULATING MANURES. 75 

to be solved, and of which the solution cannot be found 
in the stimulating properties of the plaster. 

Hitherto it has been sufficient to state the good effects 
of plaster, in order that agriculture might be enriched by 
so important a discovery. The fact alone is sufficient for 
the farmer, and it is not the only one in which the theory 
can add nothing to the practice. I shall, however, give 
here a few of my ideas upon the action of plaster ; and 
I publish them with the more confidence, because they 
appear to rne to be deduced from well-established anal- 
ogies. 

It is proved, that those salts which have a base of lime 
or alkali are the most abundant in plants. Analysis also 
shows that the different salts do not exist in the same pro- 
portions, either in plants of different kinds, or in the dif- 
ferent parts of the same plant. 

On the other hand, observation shows us every day, 
that these substances, to be beneficial to plants, must be 
presented to them in proper proportions : for if too great 
a quantity of salts easily soluble in water be mixed with 
the soil, the plants will wither and die ; though they will 
languish, if totally deprived of the salts. A little marine 
salt, mixed with dung and spread upon t!.e soil, excites 
the organs of plants and promotes vegetation ; but too 
much will produce a pernicious effect upon them. 

If we now consider that salts can act upon plants, only 
in proportion to their solubility in water, through which 
medium they are conveyed, we can conceive, that those 
which are least soluble will be productive of the greatest 
advantage. 

Water can hold in solution at any one time but a small 
portion of these saline substances ; and as they will al- 
ways be conveyed into plants in the same proportions, 
their effect will be equal and constant, and will be con- 
tinued till the soil be exhausted of the salts. The leno-th 
of this period will be according to the quantity of them 
which is contained in the soil, and to the plants not being 
rendered liable to receiving more of them than it needs. 

The solubility of plaster in water appears to be pre- 
cisely of the degree most beneficial ; 300 parts of water 
will dissolve only I of plaster. Its action is therefore 
constant and uniform, without being hurtful. The organs 
of plants are excited by it without being irritated and cor- 
roded, as they are by those salts which, being more soluble 



76 CHYMISTRY APPLIED TO AGRICULTURE. 

in water, are carried more abundantly into plants, pro- 
ducing upon them the most injurious effects. 

The greater part of those salts which are found in 
plants serve no purpose of nourishment ; they are gene- 
rally useful only as stimulating the organs and aiding di- 
gestion. Animals, as they enjoy the power of locomotion, 
can easily procure for themselves these stimulants and 
whatever is needful for the exercise of their offices, and 
they take only such quantities and in such proportions as 
are suitable for them. But plants have no other medium 
than air and water, through which to receive their sup- 
plies ; and this last transmits to them indiscriminately all 
which it can dissolve from the soil ; whence it follows, 
that the best saline manures are those that can be only 
gradually dissolved. 

This principle is applicable to all manures of whatever 
nature. There is, however, this difference in the effects of 
manures purely nutritive, and of the stimulating or saline 
manures; if the first be too abundant, the plant absorbs 
more nourishment than it can readily digest, and becomes 
affected by a kind of obesity ; the texture of its organs is 
rendered soft, loose, and spongy, and unable to give to 
their products the due degree of consistency ; whilst, on 
the contrEry, if the stimulating manures be supplied too 
profusely, and especially if they be of kinds very soluble 
in water, the organs of the plants are dried and parched 
by the excess which they receive. 

Those animal substances that are the most slowly de- 
composed, and which by their decomposition always give 
rise to soluble products, are the best of all manures : of 
this bones, horns, and wool, afford a sufficient proof 
These substances possess the advantage of affording to 
plants their suitable aliments, almost always combined 
with a stimulant, such as ammonia, of which the too irri- 
tating action is moderated by its union with carbonic 
acid or with animal matter. 

The ashes of turf and of pit coal produce wonderful 
effects upon grass lands. The first of these often con- 
tains gypsum, but frequently only silica, alumina, and 
oxide of iron. From ashes of pit coal I have obtained 
by analysis sulphuret of lime. 

The ashes, produced by the combustion of wood in our 
common domestic fires, give rise to some very remarkable 
results. Without being leached these ashes are much too 



GERMINATION. 77 

active; but after having been deprived, by the action of 
water, of nearly all their salts, and employed in this 
state, under the name of buck-ashes, they still produce 
great effect. 

The action of the buck-ashes is most powerful upon 
moist lands and meadows, in which they not only facili- 
tate the growth of useful plants, but if employed con- 
stantly for several years, they will free the soil from weeds. 
By the use of them, land constantly drenched with water 
may be freed from rushes, and prepared for yielding 
clover and other plants of good kinds. Wood ashes pos- 
sess the double property of amending a wet and clayey 
soil by dividing and drying it, and of promoting vegeta- 
tion by the salts they contain. 



CHAPTER IV. 

OF GERMINATION. 



Oxygen, heat, and water are almost the sole agents 
in the act of germination. 

Pure water, when imbibed by a seed, as a grain of 
wheat, for instance, increases its volume, and facilitates 
the developement of the germ. But the first of these 
effects is entirely physical, and takes place in the dead 
as well as in the living seed, as has been proved by M. de 
Saussure. Water changes neither the odor nor the taste 
of seeds. A grain of wheat, deprived of its vital prin- 
ciple, is, by the action of water, disposed to putrefaction ; 
whilst in one which is living, the fluid contributes to the 
developement of a succession of new powers. 

There are some seeds that can germinate under water; 
but it is only through the quantity of air contained in that 
liquid that it then operates in assisting germination. The 
developement of the germ will not take place in water 
completely deprived of air; and when the water contains 
but little air, it is necessary, to its producing the same 
effect, that the volume of it should be increased. 

Seeds, whilst germinating, absorb oxygen, and surround 
themselves with an atmosphere of carbonic acid. This, 

however, does not take place if the seed be in contact 

7 * 



78 CHYMISTRY APPLIED TO AGRICULTURE. 

with the atmospheric air, or with water containing much 
air. 

If seeds are secluded from air and moisture whilst fresh 
and succulent, they putrefy; but if previously dried, they 
do not undergo this change, but preserve their power of 
germination, till exposure to air and moisture calls it into 
action. 

The activity of germination is proportioned to the de- 
gree of oxygen contained in the air. The larger seeds 
imbibe more of this gas than the smaller. 

Seeds, whilst germinating, exhale only carbonic acid ; 
and the volume of oxygen they consume is always equal 
to the volume of carbonic acid produced. All these 
results have been ascertained by the beautiful experi- 
ments of M. de Saussure. It appears, then, that the only 
agent in germination is oxygen ; the only product car- 
bonic acid. The seed parts with a certain portion of 
carbon, and the oxygen combines with no other principle 
of the seed. For if a seed be made to germinate in 100 
inches of atmospheric air, containing 21 inches of oxygen, 
it will be found that germination has produced 14 cubic 
inches of carbonic acid, and that there remains 7 cubic 
inches of free oxygen in the portion of atmosphere in 
which the process of germination has been going on. 
It is evident, then, that, in this first stage of vegetation, 
water does not furnish the seed with any additional prin- 
ciple, and that it is not itself decomposed. It is not, 
however, useless to vegetation, since it is a well-known 
fact, that well-dried seeds may be preserved from germi- 
nation thouorh brouorht in free contact with the air. 

Water appears to me to produce two undeniable effects 
in germination. In the first place it penetrates the cover- 
ing of the seed to deposit within it the oxygen of the air 
which it holds in solution, in order to produce the forma- 
tion of the first portion of carbonic acid ; and in the 
second, it opens a free access by which the air can enter 
into the grain, and act upon it in the manner already 
pointed out. 

From what I have already stated, it follows, that ger- 
mination cannot well be carried on, unless the atmo- 
spheric air has access to the seed, which cannot be the 
case if the seed be buried too deeply in the ground, or if 
it be sown in a compact soil and closely covered over. 

It likewise follows, from these principles, that when the 



GERMINATION. 79 

earth remains a long time covered with standing water, 
the seeds must decay, and also, that a seed placed in dry 
earth cannot germinate unless it be moistened. 

The impossibility of a seed's germinating, when too 
deeply buried in the ground, explains why we sometimes 
see, after deep tilling, plants making their appearance, of 
the same kind as those which had been cultivated upon 
the soil several years before. The state of the earth as it 
regards moisture, at the time of sowing, furnishes a reason, 
independent of the action of heat, why seeds are a longer 
or shorter time in sprouting. 

Seeds do not germinate in pure carbonic acid. Mixed 
with atmospheric air this gas retards the process of ger- 
mination ; but it may be hastened by absorbing the car- 
bonic acid evolved by the seeds, by means of lime or 
alkalies. 

During the first stages of vegetation the feeble plant 
rejects those other aliments which, as it advances in 
strength, become the principal agents in its nutrition. 

Germination takes place in the same space of time in 
darkness as in light. But M. de Saussure has observed, 
that, after the process of germination was completed, the 
developement of plants was more rapid and perfect in the 
light than in obscurity. 

Thus we see, that, in the germination of seeds, every 
thing may be reduced to the following facts. 

Water, or moisture, swells the seed, and the oxygen 
contained in that liquid subtracts from the seed the 
carbon which is its principal constituent. 

The swelling of the seed by water facilitates the intro- 
duction of atmospheric air into the interior of the grain, 
where its oxygen can combine more readily with the 
carbon for the formation of carbonic acid, which is dis- 
engaged under the form of a gas. 

The heat necessary for germination facilitates the ac- 
tion of the oxygen and the volatilization of the carbonic 
acid gas, at the same time that it excites the germ and 
stimulates its developement. 

The subtraction of a portion of their carbon changes 
the state and the nature of seeds. The mucilage and the 
starch, of which they are almost entirely composed, by 
parting with a portion of their carbon, pass to the state of 
sweetish, milky substances, containing sugar, which is 
the first nourishment of the embryo plants. 



80 CHYMISTRY APPLIED TO AGRICULTUIIE^ 

CHAPTER V. 

OF THE NOURISHMENT OF PLANTS. 

As soon as a plant begins to unfold its leaves, and to 
fasten its roots in the earth, it is nourished by new 
aliments, which it receives from the air and the soil by 
which it is surrounded. 

The organs, which convey to the plant its new nourish- 
ment, are principally the leaves and the roots. The leaves 
absorb some of the gases contained in the air ; and the 
roots draw in, with the water containing them, the juices 
and salts which are mixed with the soil ; and the gases 
which are developed in it are imbibed by them through 
the medium either of air or water. 



ARTICLE I. 

The Influence of Carbonic Acid upon Nutrition. 

Plants absorb carbonic acid from water and the air. 
In the light they decompose it, and assimilate the carbon 
and a part of the oxygen. 

A small portion of carbonic acid added to that existing 
in the atmosphere is favorable to vegetation ; too large a 
quantity is hurtful. 

The presence of this gas is indispensable to vegetation, 
but the want of it is not equally great during all periods 
of the growth of plants. A very young plant, of which 
the leaves and roots have just begun to be developed, 
languishes if watered with water containing the acid. 
When it has acquired some strength and size, its growth 
and vigor are increased by the operation. Sennebier has 
observed, that young leaves decomposed, from an equal 
volume of air during the same time, less carbonic acid 
than leaves of full size. 

Vegetation can generally be accelerated by mixing with 
the atmospheric air -^^ or -^^ of carbonic acid gas ; but 
this addition is not favorable unless the plants are ex- 
posed to the sun. In the shade any addition whatever is 
injurious. 



INFLUENCE OF CARBONIC ACID UPON NUTRITION. 81 

The effects produced by mould, and many other sub- 
stances which are employed to promote vegetation, are in 
a great part owing to the carbonic acid gas, which they 
are continually transmitting directly to the plant by its 
roots, or throwing out into the atmosphere, whence it is 
imbibed by the leaves. 

The power of absorbing carbonic acid, and of decom- 
posing it, resides principally in the leaves ; and the decom- 
position is very active when they are exposed to the sun, 
in which case they give out to the atmosphere a large 
quantity of oxygen combined with a little azote. 

According to the experiments of M. de Saussure, plants 
retain a small portion of the oxygen arising from the de- 
composition of carbonic acid, and throw out the rest into 
the atmosphere. The rapidity with which the decompo- 
sition of carbonic acid is carried on, is in proportion to 
the brilliancy of the sun's rays, and to the greenness and 
freshness of the leaves. It however appears, that decom- 
position can be performed in the shade, though not very 
actively ; since Sennebier observed, that leaves which un- 
folded in the dark were sensibly tinged with green, which 
he attributes to their decomposition of carbonic acid. 

I will here mention an observation which I made, a long 
time since, in the coal mines of Bousquet, in the depart- 
ment of Beziers. 

The pieces of wood which support the roof of the long 
gallery which conducts to the beds of coal, were loaded 
with that species of mushroom which usually fixes itself 
upon the trunks of old trees ; the entrance of the gallery 
is very light, but the light gradually diminishes till it 
is lost in total darkness. I was much struck, in pass- 
ing through this gallery, with the different appearances 
presented by the mushrooms in the various degrees of 
iight; those at the entrance were yellow, and their texture 
so compact that they could hardly be broken by the hand. 
As I advanced, the reddish yellow color grew gradually 
fainter, and the texture of the plants more soft and spongy, 
till at the bottom of the gallery, where a ray of daylight 
never penetrates, I found the mushrooms, though as large 
as those at the entrance, perfectly white, and nearly with- 
out consistency, so much so, that upon pressing them with 
the hand, they were found to yield much liquid, and but 
little fibrous matter. I filled several bottles with these, 
and took in my hands some of those from the middle and 



82 CHYMISTRY APPLIED TO AGRICULTURE. 

entrance of the gallery. A comparative analysis of these 
various portions afforded me, from those which grew at the 
bottom of the gallery, only water saturated with carbonic 
acid, a small quantity of mucilage, and a little parenchy- 
mous fibre swimming in the liquid. The proportion of 
acid was much less, and that of ligneous fibre more con- 
siderable, in the mushrooms plucked from the middle and 
entrance of the gallery, particularly in the last. Those 
from the dark part of the gallery contained only the ele- 
ments of nutrition not elaborated ; whilst in the other, the 
process of assimilation was carried on more or less per- 
fectly, in proportion as light and atmospheric air had 
access to them to facilitate vegetation ; otherwise, as car- 
bonic acid was most abundant in those plants which grew 
in darkness, their texture ought to have been the most 
thoroughly impregnated with it. 



ARTICLE 11. 

The Influence of Oxygen Gas upon Nutrition. 

Healthy leaves absorb oxygen gas during the night, but 
the phenomena which they present vary according to the 
nature of the plant. Those of the oak, the horse-chestnut,, 
the false acacia, &c., absorb oxygen and evolve a less 
volume of carbonic acid than they consume of oxygen. 
The leaves of fleshy plants diminish the volume of air by 
absorbing from it oxygen, without which they sensibly 
ffive out carbonic acid. 

The quantity of oxygen absorbed by plants is in propor- 
tion to their state of vigor. It is likewise regulated by 
temperature ; being greater at 88° than at 55° or at GG"" 
Fahrenheit. 

When plants remain several nights under receivers filled 
with atmospheric air, the leaves continue, though slowly, 
to absorb oxygen, with which they are saturated as soon 
as they contain \^ their volume. When the leaves are 
saturated with oxygen they begin to form carbonic acid, 
by combining their carbon with the oxygen of the atmo- 
sphere, without at the same time changing its volume, as 
they never employ, for the formation of this acid, all the 



INFLUENCE OF OXYGEN GAS UPON NUTRITION. 83 

oxygen which they can absorb. The oxygen absorbed by 
leaves enters into a state of combination in them ; the oxy- 
gen which can be disengaged from them in a vacuum, by 
means of heat, amounts to only -^^ of the volume absorbed ; 
the gas thus extracted is not pure, but consists of azote, 
carbonic acid, and oxygen. 

It is very probable that the oxygen absorbed by plants 
growing in darkness, combines with their carbon to form 
carbonic acid ; this remains in solution in their juices, till 
the sun effects its decomposition, when the oxygen is 
thrown out into the air by the transpiration of the leaves, 
whilst the carbon enters into the composition of the 
plants. 

Plants can unfold only in an atmosphere containing 
oxygen ; nevertheless, they thrive less in the shade in pure 
oxygen, than if it be combined with other gases, as azote 
and carbonic acid. 

The leaves of different plants do not consume in the 
shade the same quantity of oxygen. Those of fleshy plants 
absorb but little, which they retain obstinately ; and dis- 
engage a still less quantity of carbonic acid. As these 
plants preserve better than others their carbon, and require 
but a small quantity of oxygen, they can live in soils of 
but little fertility : they will flourish upon heights where 
the air is much rarefied, and upon arid sands. 

The leaves of those trees which are naked during the 
winter, are, in general, those which absorb the most oxy- 
gen, and contain the most carbon. Not only do these 
plants prepare all the juices which are essential to vegeta- 
tion, and to the formation of fruits ; but after having ful- 
filled these functions, they continue to extract, from the 
earth and air, the principles of their nourishment ; these 
they elaborate and deposit between the bark and the wood, 
to serve for their first aliment at the return of spring, till 
the developement of the leaves and the excitement of the 
roots by heat, can provide for their nourishment by the 
absorption of foreign substances. The experiments of 
Mr. Knight have established this theory. 

This phenomenon in vegetation bears a close resem- 
blance to that which we observe to take place in the 
greatest number of insects, in some birds, and in many 
quadrupeds ; which become torpid during the winter, and 
are nourished, whilst in that state, by the fat deposited in 
their cellular membranes during the autumn. 



84 CHYMISTRY APPLIED TO AGRICULTURE* 

Plants growing upon marshes and bogs, and conse- 
quently surrounded the greater part of the time by an 
atmosphere of vapor, consume less oxygen gas than most 
other herbaceous plants. In general, the quantity of oxy- 
gen absorbed by plants, is in proportion to the fertility of 
the soil in which they grow, and to the quantity of gas 
contained in the air by which they are surrounded. 
These inferences have been drawn from the results of nu- 
merous experiments made by M. de Saussure. 

Healthy roots, separated from their stems, and placed 
under a bell-glass, diminish the volume of atmospheric air, 
and form carbonic acid with the surrounding oxygen ; in 
this case they never absorb a volume of oxygen greater 
than their own. If a root, thus saturated, be placed under 
another receiver filled with common air, it will form car- 
bonic acid without changing the volume of the air ; but 
if it be then exposed to the open air, it will absorb a quan- 
tity of oxygen gas nearly equal to its volume, as when it 
was enclosed under the first receiver ; which proves that 
free atmospheric air can take from roots the carbonic acid 
which they form. 

It is plain, then, that roots exercise the same action, in 
regard to oxygen, that leaves do, though they absorb less 
of it. The only important difference is, that the roots do 
not decompose the carbonic acid ; this office appears to be 
confined to the leaves, to which the acid is transported, to 
be decomposed by the solar rays. 

When the root is not separated from the stem, the re- 
sults differ from the above ; in the last instance, the root 
absorbs more than once its volume of oxygen ; the reason 
of this is very simple : the carbonic acid, as soon as it is 
formed, is dissolved in the juices of the root, passes from 
that into the stem, thence into the leaves, in which its de- 
composition is principally performed ; so that the root parts 
with the carbonic acid as soon as it is formed, and, though 
it is constantly producing, is never surcharged with it. 

Not only do the roots absorb oxygen from the atmospher- 
ic air which penetrates to them, but they disengage that 
which always exists in the water by which they are moist- 
ened. This leads to the explanation of a fact which I 
have often observed. When the roots of almost any tree 
have become surrounded by stagnant water, enclosed be- 
neath the soil, and secluded from the access of atmospheric 
air, the tree soon begins to languish, and the leaves to turn 



mFLUENCE OP AIR UPON FRUITS. 85 

yellow and die. In this case it appears that the water has 
become exhausted of oxygen, without having the power of 
renewing it, and when that is no longer present for the 
roots to absorb, they decay ; whilst, if the root were sup- 
plied with flowing water, it would be constantly receiving 
fresh supplies of oxygen for the formation of carbonic acid, 
which furnishes the principal nutrition of the plant. 

The wood, the parenchyma, the petals, and, in general, 
all those parts of plants which are not green, do not inhale 
and exhale, alternately during the day and night, the oxy- 
gen gas which surrounds them ; but they absorb a small 
quantity, which combines with their carbon, and remains 
in solution in their juices, till it is conveyed to the leaves, 
when it is decomposed by the rays of the sun. According 
to this it appears, that carbon, which forms one of the 
most abundant principles of the juices and other manures 
which are furnished to plants to supply them with nourish- 
ment, cannot be assimilated by them, unless it be com- 
bined with oxygen, and form carbonic acid. In this state 
it is thrown into the atmosphere, whence it is gradually 
absorbed by the leaves, and decomposed by them. One 
experiment, which seems to establish this opinion, is that 
of absorbing, by means of lime or the caustic alkalies, the 
carbonic acid, as fast as it is transpired by the leaves, the 
consequence of which is the death of the plant. 



ARTICLE III. 

The Influence of Air upon Fruits. 

M. Berard, in his experiments on the effect of air upon 
fruits, placed green fruits of various kinds in well-corked 
flasks, or under bell-glasses inverted over mercury, and ex- 
posed them to a strong light. After the fruit had remained 
within these glasses twenty-four hours, an analysis of the 
air, of which the volume was from seven to eight times 
greater than that of the fruit, always presented him with 
the following results. 
8 



86 CHYMISTRY APPLIED TO AGRICULTURE. 

Carbonic acid 4 

Oxygen 16.8 

Azote 79.2 



100 

In every instance, a portion of oxygen had disappeared, 
and had been replaced by a nearly equal quantity of car- 
bonic acid. The quantity of carbonic acid given out, is 
often found to be a little less than that of the oxygen ab- 
sorbed. By diminishing the quantity of air in which the 
fruits are exposed, the oxygen may be almost wholly ab- 
sorbed. Experiments made with glasses, of which the 
fruits occupied one third of the capacity, presented the 
following results. 

Carbonic acid 18.52 

Oxygen 1.96 

Azote 79.52 



100 

It appears to be proved by these experiments, that fruits 
exposed to the action of air in a well-lighted place, and 
under the successive influences of day and night, absorb 
oxygen, which combines with the carbon of the fruits, and 
forms a volume of carbonic acid nearly equal to that of the 
oxygen imbibed. 

The same changes took place when the apparatus was 
exposed to the rays of the sun, but with this difference, 
that the decomposition of the air was more prompt and 
more complete in the direct rays of the sun, than merely 
in daylight, or in the darkness of night. 

Some almonds exposed to the sun from nine o'clock in 
the morning till four in the afternoon, changed the air of a 
bell-glass as follows : 

Carbonic acid 15.74 

Oxygen 5.65 

Azote 78.61 



100 

In this instance it appears, that, besides the carbonic acid 
formed by the union of the oxygen of the atmosphere with 
the carbon of the fruit, the fruit itself furnished a small 
quantity ; whence M. Berard concluded, that fruits affect 
the air very differently from flowers. Instead of changing, 



INFLUENCE OF AIR UPON FRUITS. 87 

as the leaves do, when acted upon by the solar rays, the 
carbonic acid of the atmosphere into carbon and oxygen ; 
the fruits unite the oxygen of the atmosphere with their 
own carbon, for the formation of carbonic acid ; so that, 
in the sun, as in the shade, they absorb oxygen, and trans- 
pire carbonic acid. 

M. Berard obtained the same results when his experi- 
ments were performed upon fruits still adhering to the tree, 
and which were in full vegetation. 

The ripening of fruits appeared to M. Berard to be per- 
formed by the subtraction of their carbon, through the 
assistance of the oxygen of the air by which they were 
surrounded. When this subtraction is in any way pre- 
vented, the fruit withers and dies. 

When a vacuum is produced in receivers containing the 
fruits; or when these fruits are surrounded by an atmo- 
sphere of hydrogen, of azote, or of carbonic acid, they 
disengage at first a small quantity of carbonic acid, bat 
the quantity of it diminishes sensibly, and ceases altogether 
towards the third or fourth day. 

In every instance, green fruits remained a long time 
without undergoing any change ; they made no advance 
towards ripening, but continued stationary ; resuming, 
however, their natural action, when, at the end of several 
days, they were placed in a situation in which they could 
absorb oxygen, and transpire carbonic acid. 

When fruits are ripe they continue to absorb oxygen, 
and to form carbonic acid by the union of it with a portion 
of their carbon ; they likewise furnish a great quantity of 
this acid, which is produced by the combination of their 
own elements. 

The observations made by M. Berard upon fruits, at 
different stages of maturity, show that the same principles 
are found in them at various periods, but combined in 
unlike proportions. I will here cite only one of these 
analyses. 

Apricots, very green. More advanced. Ripe. 

Animal matter .... 0.76 0.34 0.17 

Green coloring matter . . 0.04 0.03 0.10 

Woody substance . . . 3.61 2.53 1.86 

Gum 4.10 4.47 5.12 

Sugar . . . some appearances. 8.64 16.48 

Malic acid 2.10 2.30 1.80 

Lime a little. a little, a little. 

Water 89.39 84.49 47.84 



88 CHYMISTRY APPLIED TO AGRICtTLTtJRI^. 

Cherries, currants, primes, peaches, &.C., analyzed, both 
when green and when ripe, presented the same results, 
with some slight difference in the products. 

By the process of ripening the animal matter, woody 
substances, malic acid, and water are diminished, whilst 
the sugar is considerably increased. This last substance, 
when extracted from grapes, figs, and peaches, fully ripe, 
may be partially crystallized ; whilst that from apples, 
pears, currants, cherries, apricots, and prunes, remains 
-liquid and uncrystallizable. 

When green fruits, fully grown and ready for ripening, 
are placed in an atmosphere deprived of oxygen, the pro- 
cess of ripening does not go on ; it is, however, only sus- 
pended, and will commence when the fruit is replaced in 
a situation where it can obtain oxygen ; unless it has been 
kept too long in the dis-oxygenated air. 

After ripening, fruit undergoes another alteration, which 
changes its nature ; it becomes mouldy or rotten, and in 
this state gives out great quantities of carbonic acid. The 
carbon is principally furnished by the woody portion, which 
turns brown, and by the sugar, the proportion of which is 
gradually diminished till it finally disappears ; whilst the 
oxygen can reasonably be attributed only to the decompo- 
sition of the water. I am the more inclined to believe this 
assertion, because it may be observed every day, that when 
fruits are fermenting, or decaying in heaps, a peculiar odor 
may easily be distinguished in the surrounding atmosphere, 
approaching to that of some gaseous combinations, es- 
pecially that of hydrogen with carbon. 

M. de Saussure, who repeated the experiments of M. 
Berard upon fruits, has deduced from them consequences 
somewhat different ; he believes this to arise from M. 
Berard's having enclosed his fruits in jars containing only 
six or eight times their volume of air ; the almost imme- 
diate contact of the sides of the receivers, heated by the 
sun, must necessarily have produced a change in the fruits, 
by occasioning the commencement of decomposition. 

The result of the experiments of M. de Saussure leads 
to the conclusion, that green fruits exercise the same ac- 
tion upon the air as the leaves do, though with less in- 
tensity. Like the leaves, green fruits absorb oxygen 
during the night, and give out carbonic acid, of which 
they again absorb a part. Fruits transpire oxygen in the 
sun ; when very green they consume more oxygen in the 
dark, than when they approach to maturity. 



INFLUENCE OP WATER UPON NUTRITION. 89 

The experiments of M. de Saussure have always been 
made upon volumes of air, exceeding from thirty to forty 
times those of the fruits ; and by this means the heating 
action of the sun was much diminished. 

The resuhs of the experiments of M. Berard are all 
applicable to the ripening of fruits, which was the par- 
ticular object of his attention ; whilst those of M. de 
Saussure relate chiefly to their growth. The first con- 
siders the changes they undergo when detached from the 
tree ; and if he sometimes performed his experiments upon 
green fruits, their action under his small receivers was 
like that of dead bodies. The second analyzed the phe- 
nomena of their growth ; and it is not astonishing, that 
the two should have obtained different results. 



ARTICLE IV. 

*rhe Influence of Water upon Nutrition^ 

Water influences vegetation not only by the nutritive 
principles furnished to plants by its decomposition, but by 
means wholly physical, and which we shall first consider. 

The first effect of \vater upon a soil appropriated to 
vegetation is, to moisten and divide the earth, and conse- 
quently to favor the extension of roots, the introduction of 
air, and the developement of seeds. 

The second is that of conveying to the seed the first 
aliment required by it, oxygen, which that liquid always 
holds in solution in a greater or less degree, and which is, 
as I have already observed, the principal agent in germi- 
nation. 

The third office performed by water is that of dividing 
the manure applied to the soil, of dissolving some portions 
of it, and conveying them to the organs of the plants in a 
state fitted for their digestion and nourishment. 

All kinds of w^ater are not equally suitable for this pur- 
pose ; rain water, which is the purest and . contains the 
most air of any, is also the best for supplying the wants of 
plants. Generally speaking, those streams which have 
their rise in granitic or primitive calcareous mountains, 
are favorable to vegetation ; but it is necessary that they 
8* 



do CHYJVIISTRY APPLIED TO AGRICULTURE. 

should flow through soils free from metallic salts or earths ', 
and that they should have traversed, before being used in 
agriculture, a sufficient space to have become impregnated 
with a due portion of atmospheric air. 

Streams may not be pure, and yet may be very serviceable 
for watering the soil, especially if they carry, or hold in 
solution, certain salts favorable to plants, and some animal 
or vegetable substances. In this case they possess double 
virtue, and produce double effect. 

Waters may be divided into three classes ; the first com- 
prehending those that are charged with animal matter ; 
the second, those which hold in solution some of the prin- 
ciples of vegetables ; and the third, the pure waters, or 
those which contain salts in but small quantities. 

The waters of the first class are the most active ; and 
amongst them, those which are loaded with the sweat of 
wool, or with the ammoniacal combinations arising from 
the fermentation of powdered bones, of shavings of horn, 
or fragments of wool, hold the first rank. When employed 
in their dry state, as manures, these substances produce 
their effects very slowly, but exercise a much more ener- 
getic action when, during decomposition by putrefaction, 
their products are absorbed by water as fast as formed, 
and immediately conveyed to the plants. The soft, fleshy, 
or liquid portions of animal substance do not produce so 
lasting an effect ; their decomposition is too rapid for their 
action to be continued for any length of time. 

The waters of the second class, those that are charged 
with some of the products of vegetation, either natural or 
arising from decomposition, form very good manures. 

When plants have yielded to water all their soluble por- 
tions, the subsequent decomposition of their insoluble 
fibres furnishes new soluble products, which serve for 
nourishment ; water imbibes these as fast as they are 
formed, and transmits them to the plants with which it 
comes in contact. In this manner dead plants supply 
food to the living, and all the elements composing the first 
are found differently combined in the last. 

When natural vegetable products, or those arising from 
decomposition, are mixed with, or dissolved in urine or 
the other animal fluids which are charged with salts, the 
effect upon vegetation is much increased, because, in ad- 
dition to exciting the digestive organs of plants, these salts 
dissolve some substances which could not in their original 



INFLUENCE OIP WATER UPON NUTRITION. 91 

€tale penetrate into these organs. It is for this reason 
that cakes of rape seed, wild mustard, and nuts, used in 
the manner mentioned above, afford the best manure 
known. 

The waters constituting the third class, hold in solution 
some salts ; these salts may be considered as performing 
several offices in the act of vegetation; they stimulate the 
vitality of plants, and increase the activity of their powers ; 
they produce, in fact, upon plants, the same effects as those 
produced upon the human body by the use of such condi- 
ments as marine salt, and salt-petre. Salts of the same 
nature as those contained in waters of the third class, al- 
ways produce good effects upon the soil to which they are 
applied, either by sprinkling the ground with them, or com- 
bining them with barn-yard manure. 

Though these salts are useful to vegetation, it is neces- 
sary to guard against using them in excessive portions, as 
they then dry up and destroy the plants. Lands which 
have been long overflowed by the sea, refuse to yield any 
thing to cultivation till they have, by the repeated action of 
fresh water, been freed from the salt with which they had 
become impregnated. 

Some of the salts that are conveyed into plants by water, 
exert an influence over them independent of their stimulat- 
ing power ; being decomposed within their organs, and 
serving, by the assimilation of their constituent principles, 
as nourishment to the plants. The greater part of the salts 
derived from the animal or vegetable kingdoms, are of this 
description. 

Having considered water as a mechanical power, and as 
a vehicle for the conveyance of food to plants, it remains 
for me to make known its direct influence upon them. 

M. de Saussure has proved, by experiment, that plants 
decompose water, and appropriate to their own uses the 
hydrogen and the oxygen contained in it ; but this assimila- 
tion is very trifling, if they cannot at the same time absorb 
carbonic acid. The small increase of weight gained by a 
plant in an atmosphere containing only oxygen, sufficiently 
verifies this. 

Dead plants which ferment when secluded from oxygen, 
give out some carbonic acid ; but this only proves the 
combination between the carbon and oxygen contained in 
vegetable products. 

Next to carbon, the most abundant principle in plants is 



92 CHYMISTRY APPLIED TO AGRICULTURE. 

hydrogen ; which appears to be furnished, in a great meas- 
ure, by their power of decomposing water. Hydrogen can 
be obtained from plants by distillation, but in the decompo- 
sition of dead vegetables, it unites either with the oxygen 
of the air to form water, or it is exhaled in union with car- 
bon as carburetted hydrogen. 



ARTICLE V. 



Of the Effects of the Nourishment of Plants upon the 

Soil. 

It appears to be clearly proved, that plants imbibe from 
water and the atmosphere only carbon, oxygen, and hydro- 
gen ; but analysis shows us tjiat, independently of these 
principles and the products arising from their combinations, 
plants contain azote and some earthy and saline substances, 
which cannot be produced by either of the three elements 
mentioned above. It remains then for us to inquire, in 
what manner these substances have been introduced into 
plants. 

Azote, which is found in the albumen, the gelatine, and 
the green coloring matter, is not sensibly drawn from the 
atmosphere, though it constitutes ^ of it, but passes in with 
oxygen in the water imbibed by plants, and, like that, is 
separated in their organs. 

The earths which are insoluble in water, but which are 
mixed with, or suspended in that fluid, are not absorbed in 
large quantities by the pores of plants, but may be conveyed 
into them by the aid of some chymical agents, as the acids, 
the alkalies, &:-c. Besides, if we observe attentively, we 
shall find that these substances do not abound in plants ; 
and we can easily conceive, that the little they do contain, 
might, in a state of extreme division, be introduced by 
water. 

There are some plants that fasten themselves and grow 
upon the most barren rocks, deriving from the surrounding 
air, and from rains, all the nourishment required by them ; 
of this number are the mosses, the lichens, and the fleshy 
plants. Their growth is slow, their transpiration almost 
nothing, and their color remains nearly the same all the 



EFFECTS OF PLANTS UPON THE SOIL. 93 

year round ; so that they constantly absorb water and car- 
bonic acid, and assimilate their constituent principles. 

The soil is always exhausted, in a greater or less degree, 
by the plants it produces ; and much more by those that are 
annual, than by those that are perennial. Air and water 
alone do not afford a sufficient degree of nourishment to 
plants, for when they have been made to grow in well washed 
sand, watered with distilled water, though they have flow- 
ered, their fruits did not arrive at maturity. Experiments to 
this effect have been made by Messrs. Giobert, Hassenfratz, 
de Saussure, &c. 

Those annual plants which transpire most, generally 
exhaust the soil in the greatest degree. Peas, beans, and 
buckwheat, though they have succulent stalks, exhaust it 
least, because they transpire but little. 

When annual plants are cut at the time of flowering, 
they do not exhaust the soil, as their succulent roots furnish 
materials for replacing the loss occasioned by their growth ; 
but after having produced their fruits, the soil derives but 
little advantage from the dry fibres which are the only re- 
mains of their stalks and roots. 

During fructification, plants absorb but little nourish- 
ment from the soil ; the supply necessary to the formation 
of the seed is furnished by those juices which already 
exist in the roots and stalks, and this occasions them to 
become dry and exhausted, so that, when the fruit is per- 
fected, the roots and stalks consist only of woody fibre. 
It is necessary that this fact should be known, in order 
that too late mowing of meadows, whether natural or ar- 
tificial, may be avoided. The most favorable period for 
cutting grass is that of its flowering ; if the operation be 
postponed till the seed is formed, two great disadvantages 
will arise ; the first is, that the fodder obtained will have 
parted with the greater portion of its nutritive qualities ; and 
the second, that the plants, having fulfilled all the laws of 
their nature, by providing for their reproduction, cannot 
flourish again with vigor during the same year. In sup- 
port of this doctrine, I wnll mention one w^ell-known fact, 
which is, that meadows mown before fructification af- 
ford the most abundant harvests, and the greatest num- 
ber of them, as they may be mown several times in a year. 
The perennial plants which serve as fodder, may by this 
means be preserved for several years in a state of repro- 
duction, but if mown after the formation of seed, the 
plants are weakened and the reproduction is lessened. 



94 CHYMISTRY APPLIED TO AGRICULTURE 

All farmers know, that when they subject to tillage a piece 
of artificial grass land, which has for several years been 
constantly mown at the time of flowering, it will yield 
several harvests without any dressing ; but if the grass has 
been left to go to seed, it will be necessary to supply the 
earth with manure before it will yield a good return. As 
those plants that are cut at the time of flowering do not 
exhaust the soil so much as those that remain for seed, 
the belief has arisen amongst farmers, that before the 
period of fructificartion, they are nourished by the con 
stituent principles of the surrounding air and water , but 
that during the time of the formation of the seed, then 
support is almost wholly derived from the earth. But this 
opinion will not hold in regard to all plants ; lettuce, tur- 
nips, tobacco, woad, endive, cabbages, and onions exhaust 
the soil greatly, though they are gathered before producing 
seed. Potatoes, though they produce but few seeds, impov 
erish land more than almost any other vegetable. Plants 
raised in a nursery, and afterwards transplanted, exhaust 
the soil in which they spring, more than the one in which 
they complete their growth. 

Thus we see, that during the whole time of their vege- 
tation, plants derive their nourishment from the air, and 
from the substances contained in the earth ; but if they are 
mown at the time of flowering, they leave in the soil their 
roots and portions of their stalks, which restore to the earth 
nearly as much as they have received from it; whilst, it 
they remain uncut till they have completed their course, 
they return little or nothing to the soil to compensate it for 
the nourishment they have received from it. 

It is well known to farmers, that ploughing in a green 
crop of any kind whatever, prepares the soil for producing 
well without any other manure ; since, by this process, all 
that the soil has yielded is returned to it, with some addi- 
tions, resulting from the decomposed principles of air and 
water, which are contained in the plants. 

In order fully to understand this doctrine, which appears 
to me of great importance to agriculture, it is necessary 
to consider the successive changes which take place in 
annual plants during their growth ; first, they produce 
green leaves, which, by coming in contact with the air, 
receive from it the principles of which I have spoken ; 
subsequently the stalks increase in size and number, and 
are covered with numerous leaves, which absorb from the 



EFFECTS OF PLANTS UPON THE SOIL. 95 

atmosphere a degree of nourishment suited to the increasing 
wants of the plants ; the strength, fullness, and depth of 
hue of the leaves and the stalks, particularly of the latter, 
increase in proportion to the richness of the soil. 

This state continues till after the period of flowering, 
when a change, worthy of note, takes place ; the roots dry 
up, the stalks wither and change their color; and when 
fructification is at length completed, both roots and stalks 
have become mere skeletons, which answer but little pur- 
pose either for nourishing animals or manuring earth. 
During this period of vegetation what becomes of the 
juices that were so abundant in the roots and stalks? 
They have been consumed by the formation of the seeds. 
It is undoubtedly the case that plants still continue during 
fructification to absorb some portion of their nourishment 
from the air and soil ; and this assists in the formation of 
their seeds ; but by far the greatest share of the formation 
of these is owing to the deposits contained in the organs of 
the plants. 

The same holds true of perennial plants ; and it may be 
observed, that when a tree produces fruit too abundantly it 
becomes exhausted and dried, and bears only that which is 
small and misshapen. The difference between annual and 
perennial plants is, that the former die as soon as the process 
of fructification is completed ; whilst the latter preserve 
their leaves green and their roots fresh, for the purpose of 
absorbing new portions of nourishment, to be deposited in 
their vessels for food when the returning warmth of spring 
shall cause them to require it. 

M. Matthieu de Dombasle, one of our most enlightened 
agriculturists, has confirmed by experiments the doctrine 
I have here advanced. On the 26th of June, 1820, at the 
time of flowering, he selected, within a small space, forty 
wheat plants of equal size and strength, each having three 
stalks bearing heads ; he pulled twenty of the plants with 
all their roots, and left the rest to complete their fructifica- 
tion. Having carefully freed from earth the roots of 
those he had taken up, he cut the stalks two inches above 
the base, and dried separately the roots, and the stalks 
surmounted by their heads. 

The roots and the portion of the stalks remaining with 
them weighed, grains 657 

The stalks, heads, and leaves, " 1946.5 

Total 2603.5 



96 CHYMISTRY APPLIED TO AGRICULTURE. 

On the 2Sth of August, the time of harvest, he plucked 
up the twenty plants which had been left for seed, separat- 
ing the roots, and cutting the stalks as of the first ; of these 
the weight was as follows, 





Grains. 


Roots 


419.53 


Straw, husks, and beards 


1318.75 


Grain 


1025.69 



Total 2763.97 

During these two months, the roots and the portions of 
stalks adhering to them had lost 237.52 

The stalks, head, and leaves had lost 624.67 



Total loss 862.19 

But as the seed weighed 1025.69 grains, the whole had 
increased in weight 160.47 grains, Troy. From this exper- 
iment we may conclude, that the juices contained in plants, 
at the time of flowering, contribute to the formation of the 
grain in the proportion of ^g/f .g^f , and that the excess of 
the weight of the grain, which is xo^j^f.ff, arises from the 
nourishment which the plant absorbs from the air or soil, 
during the two months of fructification. 

If the wheat is mown when in blossom, it leaves in the 
earth, to be converted into manure, a quarter part of the 
weight of the plant ; but when it is reaped after having 
come to maturity, there remains only one seventh ; and 
this last residue is worthless as manure in comparison 
with the first ; this contains almost nothing but carbon, 
whilst that is rich in juices and in decomposable matter. 
Thus we see that those plants which form seeds exhaust 
the soil most, because for all they have received they return 
nothing but their dry roots and stalks ; whilst those that are 
cut when green give back with their roots and stalks what 
they have drawn from the soil, and a part of that which 
they have drawn from the atmosphere. 

The nutritive principles contained in the soil pass into 
plants only in a state of solution, or of extreme division in 
water. Healthy plants absorb from preference those salts 
that are most congenial to them ; but if waters be charged 
with salts unsuited to their natures, they absorb the fluid 
and reject the salts till the water becomes thickened by 
them. 



EFFECTS OF PLANTS UPON THE SOIL, 97 

There are some salts which enter naturally into the com- 
position of certain plants ; the pyellitory and nettle, for 
instance, which grow upon the borders of the sea, contain 
muriate or sulphate of soda ; these vegetables, transported 
into other soils, afford no vestige of these salts, and their 
growth is less vigorous, M. le Marquis de Bullion has 
proved that the turnsol, raised in earth containing no nitre, 
does not, upon analysis, afford a vestige of any ; but that 
plants of the same kind, raised in the same soil, but wa- 
tered with a solution of nitrate of potash, are charged with 
that salt. 

Generally speaking, a superabundance of salts, especially 
if they be of kinds very soluble in water, injures vegeta- 
tion : this is particularly the case when the salts are not 
such as enter naturally into the plants, amongst the num- 
ber of their constituent principles. Salts of foreign na- 
tures cannot be useful, excepting as they may serve, in 
very small quantities, to excite and stimulate the organs of 
plants. The great value of sulphate of lime as a manure, 
is owing to its insolubility, which allows water to contain 
but a very small portion of it at once ; so that it passes 
into plants very gradually, and thus its effects are pro- 
longed for several years ; till, as I have before observed, 
the soil is exhausted of it. 

The quantity and qualityof the salts contained in plants 
may be ascertained by an analysis of the ashes arising 
from burning them in a dry state. It may not be useless 
to mention here some facts which may throw light upon 
this subject. 

Kir wan and Ruckers have proved, that an equal weight 
of herbaceous plants furnishes more ashes than of ligne- 
ous plants. M. Pertuis has found, that the trunks of trees 
afford less ashes than the branches, and these last less than 
the leaves. Evergreens yield less ashes than trees and 
shrubs that shed their leaves in autumn. On the other 
hand, Hales and Bonnet have observed, that the perspira- 
tion of herbaceous is greater than that of ligneous plants, 
and that that of evergreens is less than that of plants 
which shed their foliage. These circumstances may ex- 
plain why some plants afford more ashes than others. The 
water which is evaporated by transpiration deposits in the 
cells of the plant the salts which it had held in solution, 
and is replaced by a new quantity, which is in its turn 
thrown out, leaving behind it an additional portion of 
9 



VfS CHYMISTRY APPLIED TO AGRICULTURE. 

salts ; so that those plants, and those portions of the same 
plant, which transpire most, must necessarily contain the 
greatest quantity of salts. 

The salts and earths contained in plants are of the 
same nature as those existing in the soil in which they 
grow, but not, according to analysis, in the same propor- 
tions; because the plant absorbs more or less of them ac- 
cording to its own nature and their solubility. It cannot, 
however, be strictly said, that all the salts contained in 
plants existed previously in the soil, as some neutral salts 
are evidently formed within their organs ; such are those 
of which the acid is known to us, and particularly those 
that contain in their composition a vegetable principle : of 
this sort are the acetates, the malates, and the citrates. 
The salts do not exist after the burning of the plant, be- 
cause their acid is decomposed by the action of fire, and 
there remains only their base, which is usually potash or 
lime ; but an analysis of the plant " by the wet way " gives 
proof of their existence. 

It is even possible in some cases to follow the formation 
of the acid, by observing the progress of vegetation, and 
the changes produced in its products. Of this I will men- 
tion one example. Beets gathered late in autumn, in the 
north of France, do not yield the same principles as those 
gathered at the same period in the south of France ; the 
first contain sugar, the second salt-petre. According to 
the experiments carefully made by M. Darracq in the de- 
partment of Landes, the beet roots of the south yield as 
much sugar in the month of August and the earlier part 
of September, as those of the north ; this sugar then is 
replaced by salt-petre, of which the acid is formed during 
the progress of vegetation. It has been observed, that 
beets containing sugar frequently underwent a change 
during the winter, by which the sugar entirely disappeared, 
and was replaced by salt-petre ; in this case we can almost 
follow with the eye the process of decomposition. The 
juice of beets in which the change has commenced, when 
thrown into the boilers, becomes covered with a thick, 
white foam, which gives out a reddish vapor of nitrous 
gas: in this state the labor of extracting sugar becomes 
very difficult ; the sugar crystallizes badly, and the propor- 
tion of molasses is very great. It may be seen clearly, that 
in this state oxygen is already united in the beets with 
azote, and that only an additional portion, which would be 



CHANGES PRODUCED BY NOURISHMENT. 99 

gained during the progress of change in the roots, is want- 
ing for the formation of nitric acid ; this, combined with 
the potash, which is contained in these roots in the pro- 
portion of -j-^(y of its weight, would produce sait-petre. 

If we observe a plant during the various stages of its 
vegetation, we shall perceive at these different periods very 
remarkable differences in the odor, taste, consistency, 
6lc. ; from this circumstance we must suppose that it forms 
new products, new combinations, and consequently new 
salts. 

The alkaline salts are the most abundant in green her- 
baceous plants. M. de Saussure has observed, that the 
ashes of young plants that grew upon a poor soil contained 
at least ^ of their weight of alkaline salts, and that those 
of leaves of trees which grew from their buds contained 
at least i. 

The proportion of alkaline salts diminishes in propor- 
tion as the plants advance in age : this remark applies 
equally to annual plants and to the leaves of those trees 
that shed their foliage in autumn. The ashes of seeds 
contain a greater proportion of alkaline salts, than those 
of the plants that produced them. 

These facts are very important to those who are engaged 
in the manufacture of salts furnished by the combustion 
of vegetable substances ; since they show clearly that it 
cannot be equally advantageous to them to consume all 
sorts of plants, nor at all periods of their growth. 

Next to the alkaline salts, the earthy phosphates of lime 
and magnesia are the most abundant in plants, and, like 
the first, these diminish in quantity in proportion to the age 
of the plant. Plants also contain, but in very small pro- 
portions, silica, and some metallic oxides, especially those 
of iron. 



ARTICLE VI. 

The Changes produced in Plants by Nourishment, resumed. 

Plants are principally nourished through their leaves 
and roots : the first absorb from the atmosphere oxygen, 
carbonic acid, and water; and the second receive from 



100 CHYMISTRY APPLIED TO AGRICULTURE. 

the soil the oxygen and carbonic acid contained in it in a 
free state, or dissolved in water, and also the juices and 
salts which are mixed with the earth. 

Water appears to be the necessary vehicle of nearly all 
the nutritive portions of the soil ; so that it not only serves 
to nourish plants, by yielding to them the elements of 
which it is itself composed, but it conveys into their inter- 
nal organs all the substances which can serve them as 
food. 

The substances which chiefly afford nourishment to 
plants, present in their composition only carbon, hydrogen, 
and oxygen ; the numerous products formed in the course 
of vegetation, do not upon analysis furnish any other prin- 
ciples ; the salts, the earths, and the metals are generally 
found in them in very small quantities, and under a very 
different form from that in which they exist in the soil. 

Strictly speaking, the three principles necessary to vege- 
tation are oxygen, carbon, and hydrogen, combined in va- 
rious proportions; and it is this difference in the propor- 
tions which causes the immense variety in the vegetable 
kingdom : some hundredths more or less of carbon, oxy- 
gen, or hydrogen change the character of the body. 

The chymist in experimenting upon dead plants pro- 
duces at pleasure a part of these effects : fermeiitation and 
spontaneous decompositions give rise to a great numbept 
But the constant uniformity of the products in the same 
species of plants, and the analogy existing between those 
derived from different species of the same genus; their 
variety in the different organs, and the peculiar com- 
pounds, apparently so complicated, of each one of them, 
form altogether so many phenomena beyond the power of 
art to explain. 

We know the substances received by plants, and those 
which they reject; we determine by analysis the nature 
and the composition of the products which they form ; but 
this is the utmost extent of our knowledge. All that passes 
within the plant is still a mystery, and belongs to the laws 
of vitality, which modify by their action those physical 
laws that are known to us. 

However, as the laws of vitality governing vegetables 
are in their application less independent of the physical 
laws, than those that reign in the animal kingdom, we can 
even now raise a portion of the veil, and follow at least 
the progress of the changes, though we can as yet neither 
produce them nor discover their mode of action. 



CHANGES PRODUCED BY NOURISHMENT. lOl 

The germination of seeds and the swelling of buds in 
the spring, are almost entirely the results of physical laws : 
oxygen is the only agent necessary to produce them : wa- 
ter and heat are necessary auxiliaries, but they do not in 
any way enter into the new combinations ; they only facili- 
tate the changes that are going on. The oxygen unites 
with carbon to form carbonic acid gas ; by this means the 
mucilage and starch are reduced to the state of a milky 
liquor, which serves as the first aliment of the young plant 
or twig. 

As soon as the plant has unfolded its leaves, or the radi- 
cles of the seed have penetrated into the soil, the system 
of nourishment is changed : every part of the plant in con- 
tact with the atmosphere gives out carbon during the 
night, or when in darkness ; but the carbonic acid which 
this forms with oxygen, instead of remaining in the air, as 
at the period of germination, is absorbed principally by 
the roots and leaves, and decomposed in the last by the 
solar rays ; the carbon remaining fixed in the plant, whilst 
the oxygen is exhaled in the form of a gas. Plants are 
likewise nourished by that aqueous fluid which, constantly 
existing in the atmosphere in greater or less abundance, is, 
by the diminished temperature of the air during the night, 
deposited in the form of dew. The water contained in 
the soil dissolves the juices of the manures, and transmits 
them to the plants. 

But in order that plants should flourish, it is not suffi- 
cient that they have at their disposition all their necessary 
aliments ; it is further requisite, that the elaboration of 
these be favored by other causes possessing equal influ- 
ence over vegetation. 

I have already remarked, that leaves do not transpire 
oxygen excepting when exposed to the rays of the sun ; so 
that the carbonic acid remains in the plant during the 
whole time that the solar rays are hidden. The establish- 
ment of this fact enables us to explain many of the most 
important phenomena of vegetation : we learn from it, why 
plants that grow in the shade never produce fruits having 
the same taste, perfume, or texture as those borne by 
plants of the same kind growing in the sun ; and why the 
various sorts of fodder and green herbs are of bad quality, 
when the sun has not access to them to facilitate the 
decomposition of carbonic acid and the elaboration of the 
ffHitritive fluids. 
9* 



102 CHYMISTRY APPLIED TO AGRICULTURE- 

Independently of the light of the sun, without which 
plants cannot flourish, vegetation requires a certain degree 
of heat ; buds generally do not begin to unfold till the at- 
mosphere is at the temperature of from 50° to 54° ; and 
vegetation gains strength in proportion as the heat of the 
atmosphere increases, provided that at the same time the 
earth be sufficiently moist for the water to convey to the 
plants the nourishment it contains, and to furnish to them 
the means of transpiration. The influence of temperature 
over vegetation is so marked, that we can see the latter di- 
minish as the heat lessens, and resume its energies as that 
is augmented. Warmth renders the sap fluid, and quick- 
ens its circulation ; cold thickens it and renders it stag- 
nant. If a right degree of atmospheric temperature, the 
influence of the solar rays, or a suitable quantity of the 
aqueous fluid be wanting, the growth of plants is retarded. 
Thus we see it is not enough that plants are abundantly 
supplied with nourishment ; it is necessary that the con- 
coction of it should be favored by agents which concur in 
causinop its digestion. 

When the soil is too abundantly provided with manures, 
especially of kinds that may be easily conveyed into plants 
by water, their growth may be prodigiously increased ; but 
if the digestive organs and the constant influence of the 
sun do not concur in elaborating their juices, the result 
will be, as I have before remarked, a kind of obesity ; and 
none of the products will have either the savor or the odor 
that they would have acquired if the nourishment had been 
less abundant and better digested. It is not uncommon 
for fruits and herbs to yield the odor peculiar to the ma- 
nure with which they have been nourished, when it has 
been too abundantly supplied. 

The juices circulate in plants, not only with the same 
regularity of movement that we observe in animals more 
perfectly organized, but with a degree of force sufficient to 
carry them into all the organs, that they may receive in 
each one of them a peculiar elaboration. 

The roots absorb fluids from the earth by means of their 
capillary vessels ; but the force with which they are con- 
veyed into the internal organs of the plant, and even into 
the leaves, where their carbon combines with oxygen, is 
superior to that of capillary attraction, and the weight of 
the atmosphere. 

The celebrated Hales cut a branch of a vine four or five 



CHANGES PRODUCED BV NOURISHMENT. i03 

years old j this he cemented carefully into a glass tube bent 
in the form of a siphon, filled with mercury , by the force 
of the ascending sap alone, the mercury rose at the end of 
some days to 38 inches. M. Mirbel has confirmed this ex- 
periment, and added many others of great importance, but 
which would carry me too far from my subject. 

As the sap circulates in plants by the aid of numerous 
vessels and cells, which have no rectilinear communica- 
tion, the force with which the sap ascends may be ex- 
plained by a principle deduced from the experiments of 
M. de Montgolfier, who has proved, that, by means of a 
very small force, liquids may be raised to an almost in- 
definite height, provided the pressure of the column of 
liquid be destroyed by numerous interceptions or valves. 

The force with which the sap ascends is proportioned 
lo the health of the plants, and the abundance of its 
transpiration : a stalk deprived of its leaves will raise 
less mercury than one retaining them ; and trees having 
smooth, spongy leaves abounding in exhaling pores, such 
as the wild quince, the alder, the sycamore, the peach, 
the cherry, &C., raise it to a much greater height than 
those of which the leaves are varnished or dry. The 
beautiful experiments of Hales have verified these results. 
All the water imbibed by the different parts of plants, 
but especially by the roots, is first employed in mixing 
the juices, and facilitating their circulation ; it is then 
decomposed, and a part of it furnishes hydrogen, so abun- 
dant in the products of vegetation, but the greatest por- 
tion is evaporated, principally by the leaves, and thus 
maintains their temperature below that of the atmosphere 
during the burning heat of summer. Hales observed, 
that a sun-flower plant transpired by the leaves, in the 
space of twelve hours, 1 lb. 14 oz. of water. 

The cold which beorins to make itself felt in autumn, 
retards the movement of the sap ; the fluids become 
thickened, the solids contracted, the leaves cease to in- 
hale, and the roots no longer absorb nourishment from 
the soil, and at length the vital functions are suspended. 
The returning warmth of spring brings renewed life to 
the organs ; the fluids and the solids receive a greater 
expansion, circulation is restored, and the sap deposited 
in the vessels during the summer and earlier part of au- 
tumn, aflbrds the first nourishment to plants. 

The branches of trees that are lopped off" in winter, put 



104 CHYMISTRY APPLIED TO AGRICULTURtl. 

forth buds and stalks in the spring ; a branch of a nne 
introduced during the winter into a hot-house, vegetated 
as it would have done in the spring, whilst that portion of 
it which remained exposed to the cold experienced no 
change. Plants that have been browsed in autumn, do 
not put forth so early, nor with so much strength as those 
of which the roots, and the parts immediately surmounting 
them, have been preserved by mowing. 

All agriculturists have observed, that young trees trans- 
planted in the spring appear to flourish for three or four 
months, and then die ; if when taken up they have ex- 
amined their roots, they have almost invariably found 
that they presented no appearance of having increased ; 
which proves that vegetation is carried on in the spring 
by the nourishment provided, and deposited in plants be- 
fore the fall of the leaves. 

The difference which exists in the vegetation of the 
same branch, one end of which is placed in the earth, 
and the other rising above it, must strike every observer. 
The part which is planted in the soil, sends forth roots, 
whilst that which rises into the air produces leaves ; and 
if any part of the root be uncovered, so as to come in 
contact with the air, it produces stalks and leaves ; whilst 
that which remains beneath the soil continues to grow as 
the root of them. All parts of plants then are organ- 
ized by their growth in such a manner, as shall enable 
them, most conveniently, to imbibe at the same time their 
nourishment from the soil and from the atmosphere. 

It is in the power of art to influence the flow of the 
sap, nearly at will. When the nourishment afforded by 
the earth is too abundant, it is but imperfectly digested, 
and is exclusively employed in the growth of the plants; 
a tree in this case produces neither flowers nor fruit, but 
expends all its strength in leaves and wood. To remedy 
this superabundance of sap, some of the roots may be 
separated ; or what is still better, incisions may be made 
in the bark of the tree to cause the escape of a portion of 
the sap. 

If it be wished to facilitate the growth of the fruit, a 
portion of the branches may be pruned, and part of the 
fruit be plucked off"; in this way a greater quantity of 
sap may be supplied to the fruit that remains ; tight 
ligatures upon the branches, and incisions surrounding 
them through the whole thickness of the bark, produce 



CHANGES PRODUCED BY NOURISHMENT. 105 

the same effect. The pruning of fruit trees is principally 
designed to limit the production of fruit to the quantity 
that can be properly nourished by the plant. The graft- 
ing which is practised upon trees of analogous species, 
only presents to the juices of the wild tree an organic 
tissue different from its own ; in the cells of which the 
juices receive a peculiar elaboration, which changes the 
nature of their products. 

It is not by an analysis of plants, nor by the proportion 
of their constituent principles, which can be extracted by 
water, that we can judge of the nutritive quality of vege- 
tables, or other alimentary substances. I have already 
proved, that a nutritive substance, deprived of all its solu- 
ble parts by water, is capable, in the progress of its de- 
composition, of forming new and soluble compounds. It 
is only by experiments, and by the effects of this or that 
kind of food upon animals, that we can ascertain the 
differences existing between various nutritive bodies. 

The digestive juices of the stomachs of animals and 
the organs of plants animated by vital powers, of which 
we are ignorant, have also their chymistry, with which 
we are unacquainted, and of which we can understand 
only the results. It is surely erroneous to pretend to 
determine the quantity of nourishment, by that portion 
which can be extracted from any article of food by water ; 
but upon this principle Davy has represented the nutritive 
virtue of beets by the number of 136, and that of carrots 
by 98; whilst M. Thayer has by his experiments estimated 
that of the first to be 57, and of the last 98. Upon the 
same principle Davy has valued the effects of linseed 
cakes at 151, compared with those of beets as 136 ; 
while it has been proved that 70 lb. of beets are hardly 
equivalent in nourishment to 10 lb. of linseed cakes. 

In order to estimate the nutritive merits of any sub- 
stance, it is necessary to have less regard to its chymical 
character, than to the nature of the animal to be nourished 
by it : one is disgusted by that which pleases another ; 
and this will decompose what that will reject ; it is only 
by observation that we can decide. 

These principles are still less applicable to the nourish- 
ment of plants, than of animals ; because of the first it 
is necessary that their food should be presented to them, 
and in a state of solution or mixture ; whilst the last seek 
theirs where it m.ay be found, and make choice of such 



106 CHYMISTRY APPLIED TO AGRICULTURE. 

as is suitable for them ; but in both cases the nutritive 
virtues of the food can be estimated only by the results 
of its elaboration in the digestive organs, and by the 
effects produced on the economy of the animal or vegeta- 
ble. It should besides be remembered, that the nutritive 
qualities of the various products of vegetation depend 
less upon their weight, than their kind ; and that a sub- 
stance may be insoluble in water, which may, when acted 
upon by the gastric juices, become excellent food. 



CHAPTER VI. 

IMPROVEMENT OF THE SOIL. 



To improve the soil is to render it more suited to vege- 
tation by ameliorating the nature of the earth. All then 
which tends to dispose a soil favorably towards plants, in 
connection with the action which is exercised upon them 
by air, water, temperature, manures, ^c, may be justly 
termed improvement. Thus, before undertaking to im- 
prove a soil, it is necessary to be acquainted with its 
qualities, and particularly with its defects, that we may 
apply to it the means of improvement it requires. 

This preliminary knowledge of the defects of a soil 
implies a second, which is that of all the agents which 
can be employed in its improvement : the correction of 
known faults can only be performed by means of sub- 
stances possessing opposite qualities. 

As in the term improvement is implied all which can 
tend to ameliorate a soil, it necessarily has a very exten- 
sive signification ; it comprehends operations purely me- 
chanical, and the use of those earthy and nutritive mix- 
tures, which are produced by art ; it likewise comprises 
all the means which can be employed to direct advanta- 
geously the action of air, water, heat, &,c. It is in all 
these relations, that it is necessary to consider the great art 
of improvement. 

The best earths produce but little, if they be not stirred 
by the spade, the hoe, or the plough. This operation 
divides and softens the earth, brings to the surface the 
manures of all kinds, which the rains had caused to sink 



IMPROVEMENT OF THE SOIL. 107 

below it ; facilitates the spreading of the roots, mixes the 
dung with the earth, and renders its action more equal ; it 
destroys weeds, and causes them to serve as manure ; and it 
frees the soil from vermin, which would otherwise multiply 
in it to the destruction of the harvests. 

This operation is performed upon all soils of what kind 
soever ; it forms the very basis of agriculture ; without it 
there can be no harvest. The tillage by the hoe is much 
more perfect than that by the plough, but the spade is a still 
more efficacious implement. The plough divides and turns 
the soil with less exactness than either of the others ; and 
notwithstanding the crossed and multiplied furrows, there 
will be some portions of the intervals and intersections, 
where the soil will remain untouched ; but as tillage by the 
plough is the least costly, and the most expeditious, it has 
generally received the preference. 

I know a little village in Touraine, between the Cher and 
the Loire, where all the lands are cultivated by the spade, 
and their produce is always double that of any in the 
neighbourhood ; the inhabitants have become rich, and the 
soil has doubled in value. In Bremont, between Loches 
and Chinon, they employ no other means of cultivating a 
very fertile soil ; but this method can be used only on small 
estates, or in a country where labor is very abundant and to 
be procured at a low price : I do not doubt, however, that 
there are some localities where it could be conducted with 
profit, if it should be employed from time to time to 
ameliorate successive portions of land, especially those 
that have been used for the cultivation of such plants as 
have loner roots. 

In the alluvial soils formed by the deposits of the Loire, 
between Tours and Blois, the farmer reaps from his land a 
harvest of corn, and afterwards lets it to persons, who turn 
it to the depth of a foot, with spades, and raise upon it legu- 
minous plants. 

From the effects produced by this kind of tillage, we may 
perceive, that it cannot be employed equally in all soils, or 
indifferently at all seasons, nor be always carried to the 
same depth. A light, porous, calcareous, or sandy soil 
requires less tilling than that which is compact and argilla- 
ceous ; and this last requires to be stirred more deeply 
than the first, because otherwise the roots cannot penetrate 
it and fasten themselves in it ; neither can the air gain 
access to deposit upon them its kindly moisture. 



lOS OliVMlSl'R^ AfPtiED Td AGKICULTtlRET/ 

CalcareouSj sandy, and siliceous soils may be tilled at 
any time, whilst the argillaceous soils are in a fit state for the 
plough only at certain seasons, which must be eagerly 
seized upon by the farmer ; the action of the plough upon 
these lands immediately after rain, only leaves marks in 
the mud ; and if they be allowed to remain till they are 
thoroughly dry, they become impenetrable by it ; the in- 
terval between these two periods is the time most favorable 
for tilling. 

The best tilling does not always prepare soils entirely for 
cultivation ; some are not sufficiently divided or crumbled ; 
others are not sufficiently levelled, and it is only by the as- 
sistance of the harrow, or the roller, that the labor of tillage 
cari be completed- By dragging the harrow in all direc- 
tions over a nevi^ly ploughed field, the clods left by the 
plough are turned over, the uprooted weeds are carried off, 
and a more equal division is given to all parts of the soil. 
The strength and weight of the harrow must be in propor- 
tion to the resistance offered by the nature of the soil. The 
harrow can be employed advantageously in opening the soil 
of artificial meadows^ especially those of clover, when the 
surface has become a crust impenetrable by air or water ; 
the operation of harrowing, in this case, should be performed 
early in the spring of every other year, or immediately after 
having cut the first crop of fodder; by this means, many 
plants injurious to the soil are destroyed, and meadows are 
restored, which would have been constantly deteriorating. 
I have practised harrowing fields of grain, early in the 
spring, with great success, and have found the harvests 
from them uniformly much finer, than from those that had 
not been harrowed ; but it was necessary to pay attention 
to having the harrows very light, and made with wooden 
teeth. 

The roller I have found to produce an excellent elTect 
after the seed was covered ; it unites and levels the surface 
of the ground, and is particularly useful for porous and light 
soils, and for those earths of which the constituent particles 
are fine and light. If such soils have not received a suitable 
degree of firmness from the roller, high winds and rains 
are apt to carry off the upper layer, and to leave bare the 
roots of the plants. Another advantage arising from the 
application of the roller is, that the soil which has been 
subjected to it, presents fewer obstacles to the use of the 
scythe, or of the sickle. 



IMPROVEMENT OF THE SOIL. 109 

When frosts have bound up the soil, and it has been 
again set free by thaws, the roots are left ahuost without 
support, as the earth scarcely adheres to them : the roller, 
applied to lands as soon as they are firm enough to admit 
of its being passed over them, is very useful, as it reunites 
the earth to the roots, and repairs the injury done by the 
frosts and thaws. 

A judgment of the mixture necessary for amending a 
soil, can be formed only from a perfect knowledge of its 
defects. 

A soil in the composition of which the best earths are 
united, does not need to be improved by the addition of 
new earthy principles : good tillage and the application of 
manure are sufficient to render it fertile : but that soil in 
which any one of the earths predominates to such a degree, 
as to give a character to the whole mass, requires to be 
corrected by the admixture of substances possessing oppo- 
site qualities. I shall distinguish soils as argillaceous, 
calcareous, siliceous, and sandy : these divisions seem to 
comprise all those requiring to be amended ; and the quali- 
ty of the earth predominating in each, indicates sufficiently 
the kind of improvement suitable to it. 

An argillaceous or clayey soil is rendered pasty by 
rains, and it is hardened and cracked by heat ; it absorbs 
moisture from the air only on its surface, but it imbibes 
abundantly the water of rains, and retains it by so strong 
an affinity, that when the supply is in excess, it remains 
till it stagnates and causes the roots of plants to decay. 

An argillaceous soil is unfavorable to cultivation ; for 
when it is acted upon by the frost, the water contained in 
*ts interstices expands by freezing, and the thaw which 
sets the earth free, divides it into morsels with which the 
roots of plants have so little cohesion, that they may be 
drawn out from it almost without resistance : the roots are 
at such times in the state of newly planted vegetables ; they 
have need of being established, of being fixed to, and 
united with the soil, in order to vegetate. If in this state a 
root be attacked by a new frost, it dies ; for not being pro- 
tected by the close adhesion of the soil, the cold acts upon 
it, as if it were exposed defenceless upon the surface : it is 
this which renders alternate frosts and thaws more injuri- 
ous to fields of grain, and to artificial meadows, than the 
severest cold which continues till spring. It is to obviate 
10 



110 CHYMISTRY APPLIED TO AGRICULTURE. 

this evil resulting from a second freezing, that I propose 
levelling the earth by the roller, after the first thaw. 

These defects, more marked in argillaceous soils than 
in others, require to be amended ; every thing which will 
tend to soften the earth, to render it more light and po- 
rous, and to facilitate the passage of water through it, is 
perfectly adapted to this kind of soil : thus the mixture of 
earths, and of calcareous sands, broken shells, chalks, and 
lean marl ; deep and frequent ploughing ; the turning in of 
green crops ; the use of hot manures, such as the dung, 
fresh from the barn-yard, of sheep and horses, that of 
pigeons and fowls, poudrette, and the salts, are so many 
means which may be made to concur in the improvement 
of argillaceous soils. 

I have had opportunities of seeing many soils possessing 
the same faults as the argillaceous, but not owing to the 
excess of that earth ; for by mixing a portion of the soils 
in water, I satisfied myself that there was not contained in 
them any coarse sand ; so that the whole was formed by a 
union of particles so minutely divided as to present no 
consistency in the mass ; but forming a paste with water, 
and cracking when that liquid was evaporated. The only 
difference between the argillaceous soils and these is, that 
the latter when dried do not possess the hardness of the 
former, but on the contrary fall, under the pressure of the 
hand, into a nearly impalpable powder. The state of these 
soils is owing to their having been exhausted by long cul- 
tivation : some of the kind which I have owned, I have 
been able to restore to fertility by applying a portion of 
sandy marl containing -^^^ of calcareous sand. 

Calcareous soils possess properties entirely opposite to 
those of the argillaceous soils ; the rains filtrate easily 
through them, and they throw off moisture readily by evap- 
oration ; the air can penetrate them, to deposit amongst 
their particles the moisture with which it is charged : and 
this, especially in hot climates, conduces greatly to their 
fertility. The tillage of these soils is always easy ; and as 
they are light and porous, provided they have sufficient 
depth, roots spread in them easily. Though, from their 
character, these soils do not require so much amendment 
as those that are argillaceous, they may still be im- 
proved ; especially by giving to them the power of retain- 
ing water for a longer time, that they may thus be better 
able to supply the wants of plants : for this purpose, it is 



IMPROVEMENT OF THE SOIL. Hi 

sufficient to add to them some fat marl, or, for want of 
that, calcined clay. These soils, being naturally warm, 
require the fresh dung of neat cattle ; the unctuous ma- 
nures are best adapted to them. 

Sand incorporated with finely divided calcareous earth, 
forms an excellent means of amendment, especially if it 
be combined with clay or fat marl. I have likewise seen 
the rich mud drawn from rivers, used with great success 
in improving calcareous soils. 

There is a great resemblance in many respects between 
sandy and siliceous soils : both are formed, generally, by 
the alluvion of rivers ; both of them are nearly barren 
when they contain no other principles ; and both of them 
form the base of very good soils, if they are suitably 
amended. 

When these soils are formed by the inundations of rivers, 
or by streams that have taken new channels, they are for 
some time destitute of fertility ; but the successive swell- 
ings of the rivers deposit a rich mud, which becomes at 
length incorporated with the first layer ; and when the 
whole is well united, an excellent soil is formed. This 
mud is very fertilizing, from its containing the remains of 
all those animal and vegetable substances, Vvhich muddy 
waters carry with them in their overflowings. When these 
soils are left to themselves, we see plants springing up on 
them spontaneously, from the seeds deposited by the waters 
which conveyed them there. 

Soils of this kind rarely require manuring : successive 
inundations constantly renew their fertility : their level is 
raised by the accumulation of deposits, till at length they 
are not subject to being overflowed, excepting when the 
rivers rise unusually high ; and in those cases the large 
pebbles, which never float upon the surface of water,, can- 
not be deposited upon them. These lands, so valuable for 
agriculture, do not oflTer much resistance to the rapid 
current of great inundations, which often carry them oflE*; 
nor to the masses of ice, which at the breaking up of the 
frosts gully and furrow them. I believe I ought here to 
devote a few lines to pointing out some methods for pre- 
serving these valuable lands from such accidents : it is of 
more consequence to preserve property than to improve it. 

In order to prevent the evils of which I have just spoken, 
it is customary to surround lands of this kind with planta- 
tions of trees; but trees of a large size cannot take root 



112 CHYMISTRY APPLIED TO AGRICULTURE. 

firmly in a sandy and easily disturbed soil. The winds 
are generally very violent in those valleys through which 
large rivers flow ; and these, by the violent motion which 
they give to the branches, twisting them in every direc- 
tion, loosen the roots ; and the earth being continually dis- 
turbed, the water penetrates in, and softens it, so that when 
an overflow of the river happens, the breaches thus made in 
the soil lessen its powers of resistance to the flood. 

If we observe carefully the action of currents upon the 
great trees surrounding lands situated upon the banks of a 
stream or river, or upon an island lying in the course of 
one, we shall be convinced, that, so far from preserving, they 
facilitate the destruction of property ; for as the trunks op- 
pose an invincible resistance to the force of the current, it is 
divided, and, encircling them, it meets again, having formefJ 
a complete trench in the soil. Thus, though large trees 
may be useful for turning aside masses of ice, and prevent- 
ing the land from being much injured by them; yet in- 
stead of preserving it from the ravages of a rapid current, 
they become powerful auxiliaries to its destructive action. 

Flexible shrubs are undoubtedly preferable to large trees ; 
their roots bind the soil ; their branches lie upon the sur- 
face of the earth, and preserve it from injury during floods ; 
but these shrubs do not present any resistance to the ice 
when the rivers are breaking up ; they cannot turn aside 
the masses of it, and force them to remain in the bed of 
the river, that they may not furrow the meadow or field. 
Il is necessary then to unite the resistance offered by trees 
with that of flexible shrubs : in order to do this, it is neces- 
sary to plant willows or poplars on the extremity of the 
banks, at the distance of seven or eight feet apart ; the 
heads of these may be cut off" some feet above the height 
to which the highest floods ever reach ; the water willows 
or osiers may be planted all along upon the shelf or slope 
of the land, and from twenty-five to thirty feet inward. In 
a few years there will be nothing to fear from floods or ice 
upon land defended in this way ; and a considerable reve- 
nue will arise from the pruning of the trees, and the clip- 
pings of the osiers. 

After having placed the land out of danger from inunda- 
tions, the neighbourhood of a river opens sources of profit 
that are very simple, and may be taken advantage of at a 
slight expense. I have heretofore remarked, that the mud 
of rivers is of great use as an amender of soils, and that 



IMPROVEMENT OF THE SOIL. 113 

when employed upon alluvial lands it supersedes the ne- 
cessity of applying to them other manures ; it is then ad- 
visable, in overflowings, to retain that mud, and that only, 
which possesses the greatest power of fertilization. 

When the overflow of a stream commences by inun- 
dating that portion of land which lies highest up the cur- 
rent, it spreads with great rapidity over the whole extent 
of it, furrowing its surface, and carrying beyond it all the 
most finely divided mud with v/hich it is loaded ; often up- 
rooting crops and washing away the manures which have 
been deposited during former overflowings ; and thus im- 
poverishing instead of enriching the soil. But when the 
rise of water begins down the current, and the whole tract 
of land is slowly submerged, till, even to the head, it is 
under water, the soil receives and retains all the richest 
and most finely divided mud, as well as the remains of 
animal and vegetable substances which the stream has in 
its downward course washed ofl' from other tracts of coun- 
try, without any injury being sustained either by the har- 
vest or the land. In order to give the desired direction to 
the current, it is only necessary to raise the head of the 
land, or that part which lies up the stream, and to plant 
the bank with osiers. 

By these means, I have improved and tripled the value 
of certain islands belonging to me in the river Loire. These 
islands, which formerly produced but little, and were con- 
stantly receiving injury from the swellings of the river, are 
now the most productive portions of my estate, for the cul- 
tivation of grains and beet roots. 

When sandy or siliceous soils are situated at a distance 
from a river, or are by the height of the banks placed 
beyond the reach of an overflow, it is necessary to amelio- 
rate them by art ; and this must be done by the addition of 
fat marl, clay, dung, &c. The amendments must be varied 
according to the nature and fineness of the sand : calcare- 
ous sands retain moisture better than siliceous sands. 

I hav^e seen some soils formed of beds of large pebbles, 
whicli, without the appearance of mould upon the surface, 
produced very good crops : the layer of pebbles, which was 
second from the surface, contained earth enough to enable 
the plants to take root and flourish. 

Soils of this kind furnish excellent pasture for sheep, as 
may be observed on the ancient and immense alluvions of 
the Durance and the Rhone. The herbage upon these is 
10* 



114 CHYMISTRY APPLIED TO AGRICULTURE. 

excellent, and suffers less from drought than elsewhere; 
being protected from the ill effects of the scorching rays of 
the sun, by the pebbles lying above its roots. 

Rozier made the experiment of covering a part of the 
soil of his vineyards with pebbles, and found it attended 
with good effects, especially as it regarded the quantity of 
wine obtained. One of my friends owned in Paris, near 
the barrier d'Enfer, an enclosure, of which the soil was so 
dry and poor, that notwithstanding all the pains he be- 
stowed upon it, he could never make any fruit trees thrive 
there : in order to amend the soil, he covered it with a 
layer of good earth, which he mixed with the dry sand of 
the spot ; this gave it some degree of fertility ; but the heat 
dried his plantations so much, that he could only preserve 
them by frequent and very expensive waterings : he at 
length concluded to cover the surface of the ground with a 
layer of pebbles, and from that time the trees prospered. 

In some countries, recourse is had to fire, as an amender 
of the soil : this process, called burning, is strongly recom- 
mended by some practical farmers, and highly disapproved 
of by others : both sides rely on the test of their own ex- 
perience ; and both are so sincere in their opinions, 
that it would be useless to contest the truth of their ob- 
servations. I can only agree with each of these contra- 
dictory opinions, and at the same time make known the 
cases to which burning is applicable, and those to which 
it is unsuited, in order to enlighten the agriculturist as to 
the effect of the operation : he can afterwards make for 
himself just and rational applications of the theory. 

In the process of burning, a layer of from two to four 
inches in thickness, is removed from the soil in clods : 
little heaps of combustibles are formed with the broom, 
thistles, fern, and shrubs that grow upon the spot : these 
are covered with the clods, and at the end of some days 
are set on fire ; the combustion of them lasts a longer or 
shorter time. When the whole has become cool, the heaps 
of ashes are spread over the surface, and thus mixed with 
the soil. 

By this operation the constituent parts of a soil are di- 
vided, and rendered less compact ; the disposition which 
a clayey ground has to absorb a great quantity of water, is 
corrected, and this soil rendered less cohesive and pasty ; 
the inactive vegetable matter contained in it, is converted 
into manure : the oxidation of its iron is carried to its 



IMPROVEMENT OF THE SOIL. Ij5 

maximum ; and insects and the seeds of injurious plants 
are destroyed. Hence we perceive that burning belongs 
to moist, compact soils; it is attended with good effects 
when the bed of earth is too cohesive, or when it presents 
veins of blackish oxide of iron : it is suited to nearly all 
cold and compact lands. 

Burning, especially if it be judiciously conducted, com- 
pletely changes the nature of a soil, and corrects the great- 
er part of its imperfections. 1 have by this means given to 
agriculture 120 acres of land repuied sterile, formed almost 
entirely of a ferruginous and very compact clay : the burn- 
ing extended to the depth of four inches. For twelve years 
this land, though not very productive, has afforded me good 
returns. Its former sterility had procured it the name of 
the Jews' heath. 

Burninor is hurtful to calcareous and liaht lands; to 
soils of which the composition is perfect ; and to fertile 
lands, rich in decomposed animal and vegetable sub- 
stances. 

It is useless to soils purely siliceous, for these can receive 
no modification from fire. 

In some countries it is customary to burn the stubble 
upon the field ; this method, which is only an imperfect 
mode of burning, is productive of good in two ways ; in 
the first place, it purifies the soil from insects, and from the 
seeds of noxious plants ; and in the second place, it forms a 
thin layer of carbon, which by its extreme division is capa- 
ble of being easily absorbed by plants. I believe that even 
the heat occasioned by the combustion of the stubble and 
herbs covering the soil, may produce salutary changes in 
the combinations of the constituent parts. 

The results which I obtained from mixing calcined clay 
with the sand constituting the soil upon a portion of the 
plain of Sablons, near Paris, has led me to think, that 
whenever lands of this nature are cultivated, it may be 
useful to amend them by the same process : in order to do 
this, clay may be formed into balls by moistening it with 
water enough to reduce it to a paste ; these balls, after 
having been calcined in a lime-kiln, or the oven of a pot- 
tery, may be pounded, and the fragments mixed with the 
soil. Calcareous, siliceous, and sandy soils may be in this 
way much improved. 

Of all the agents which may be employed as amend- 
ments, there is none of which the action is more powerful 



116 CHYMISTRY APPLIED TO AGUICULTURt' 

than that of water : not only does it contribute to the 
nourishment of the plant by its decomposition, which de- 
posits in the vessels its elementary principles ; but it acts 
still farther by promoting the fermentation of manures, 
and by conveying into the vegetable organs the juices 
and salts. Independently of these properties, water di- 
lutes the sap, which has become thickened in the body of 
the plant, and facilitates its circulation ; and likewise fur- 
nishes abundantly the means of transpiration. The soil is 
also softened by water, and thus rendered more permeable 
by the roots, and by atmospheric air which supplies them 
with the moisture it contains. 

All the excess of water absorbed by plants, is thrown 
off by transpiration ; and this transpiration is always more 
or less abundant in proportion to the quantity imbibed. 

The custom of inundating meadows during winter, pre- 
serves them from the effects of hard frosts. Davy ascer- 
tained the temperature beneath the bed of ice covering a 
meadow, and above it : beneath the ice his thermometer 
stood at 43° ; above the ice at 29°. Every one must have 
observed, that when the surface of a meadow is only par- 
tially covered by water during the winter, the herbage 
upon that part which is left dry, is withered and nearly 
dead, whilst the rest retains its green hue, and continues 
to grow. 

The character of water used for irrigation, is a thing of 
some consequence; that of a living stream is the bes* 
especially i^ it have, by a long course, become impregnated 
with a gooa quantity of atmospheric air. 

Though water is the most active agent in vegetation, it 
is nevertheless necessary to apply it with reserve and cau- 
tion : the worst effects are produced by irrigating land so 
often as to keep the soil constantly in the state of a liquid 
paste. The first evil arising from such a course is that of 
increasing the size of the plants to the injury of all their 
other qualities ; for in such a case the fibres of plants be- 
come loose ; the texture soft and watery ; the flowers are 
inodorous, and the fruits without firmness, taste, or perfume. 
The second is, that all useful plants which do not require 
much water, give place to rushes and flags, which change 
and ruin the soil : in this case the same evil is produced 
which we seek to destroy in wet lands by the use of soot, 
gravel, ashes, and other absorbing and saline bodies. 

Frequent irrigations are not injurious to poor, light. 



IMPROVEMENT OF THE SOIL. 117 

sandy, or calcareous soils, which have much depth ; but 
they are injurious to rich, compact, argillaceous soils; for 
in such the noxious plants of which I have just spoken, 
readily establish themselves. 

To ascertain the most favorable times for irrigation, it 
is necessary to consult the state of the soil, and of the 
plants ; when the earth is deprived of moisture to such a 
depth that the plants languish, and begin to lose their 
leaves, the favorable moment has arrived for watering 
them. If allowed to remain in this state too long, they 
cease to grow, and hasten to terminate their vegetation by 
the production of fruits and flowers; but these are always 
feeble, poor, and incomplete, when produced under such 
circumstances. 

The custom of allowing lands to lie fallow after having 
produced several harvests, has descended from the re- 
motest antiquity, and is still followed in the greatest part 
of Europe. It has been thought necessary, that land, after 
having been exhausted by two or three successive crops, 
should be allowed to rest, or to remain in fallow during 
one or two years, in order that it might have time to re- 
cover its strength, or productive virtue. The necessity 
for rest, imposed by nature upon all animals after con- 
tinued action, undoubtedly gave rise to this practice; and 
though the supposed analogy between living bodies, and 
those that are not so, has no rational foundation, yet it has 
confirmed the custom of fallowing which arose from it. 

However, I am far from believing that this was the only 
cause for the adoption of the method of which I am 
speaking : I believe that it may be attributed to the want 
of hands for performing the labor of constant cultivation, 
or to the impossibility of nourishing a sufficient number of 
animals to furnish the necessary manures. 

The extent to which the cultivation of lands should be 
carried, ought always to be in proportion to the popula- 
tion to be fed by its products. It is to be presumed, that 
when the globe had fewer inhabitants, the settlements 
were made in those spots where the soil was most fertile, 
and that when these were exhausted, they removed else- 
where ; but when property came to be divided and marked 
out, each cultivator confined his labors to such a por- 
tion of land as would supply his wants; so that when it 
was sufficient for him to cultivate one quarter, or one 
third of his territory, he allowed the rest to remain un- 
tilled. 



118 CHYMISTRY APPLIED TO AGRICULTURE. 

Fallowing has, according to this view of the subject, 
arisen from necessity. We know with certainty that the 
crops in gardens surrounding dwellings may be multiplied 
and continued indefinitely, by means of tilling and manur- 
ing ; but the necessity for this is not felt, as long as the prod- 
uce is sufficient for consumption, and when the expense 
attending the means of procuring an increase beyond that, 
would be so much clear loss. 

In proportion as population has increased, lands have 
been cleared up, and cultivation extended and improved ; so 
that production has always kept pace with consumption. 
As the wants of society permit fallowing less at this time 
than formerly, it has begun to disappear, especially where 
those wants are most pressing ; and more particularly, when 
there is an assured prospect of an advantageous market for 
agricultural productions. 

Fallowing was necessary as long as grains only, all of 
which exhaust the soil, were cultivated ; during the intervals 
of tilling the fields, a varieiy of herbs grew in them, 
which afforded food for animals, and the roots of which, 
when buried in the soil by the plough, furnished a great 
part of the necessary manure. But at this day, when we 
have succeeded in establishing the cultivation of a great 
variety of roots and artificial grasses, the system of fallow- 
ing can be no longer supported by the shadow of a good 
reason. 

The scarcity of dung occasioned by the limited number 
of cattle that could be maintained upon a farm, caused the 
custom of fallowing to be continued ; but the ease 
with which fodder may be cultivated furnishes the means 
of supporting an increased number of animals; these in 
their turn supply manure and labor; and the farmer is no 
longer under the necessity of allowing his lands to lie 
fallow. 

Artificial grass lands ought now to be considered as 
forming the basis of agriculture ; these furnish fodder, the 
fodder supports cattle, and the cattle furnish manure, labor, 
and all the means necessary to a thorough system of culti- 
vation. 

The suppression of the practice of fallowing is then 
equally serviceable to the cultivator, who increases his pro- 
ductions without proportionally increasing his expenses, and 
to society, which derives from the same extent of soil a 
much greater quantity of food, and additional resources for 
supplying the work-shops of the manufacturer. 



IMPROVEMENT OF THE SOIL. 119 

A great advantage has arisen from the system of a ro- 
tation of crops, which has succeeded that of fallowing. 
By skilfully arranging a succession of crops of grain, 
artificial fodder, leguminous plants, roots, &-c., the earth 
is enriched, instead of being impoverished ; the ground 
is cleansed from weeds, and more abundant crops are ob- 
tained at a less expense. During those years when cer 
tain fodders, such as clover, sainfoin, and trefoil, require 
no other care than that of harvesting them, the farmer 
can bestow all his attention, manures, and the labor o 
his cattle, upon such other portions of his farm as may 
need amelioration ; so that, instead of having one third 
of his land lying as an unproductive fallow, it may be 
covered with herbage affording the finest food for cattle. 
The soil will be growing richer instead of poorer, and may 
be prepared for raising grain, without the addition of any 
manure. 

What has contributed the most towards confining French 
agriculture to that state of mediocrity, from which neither 
the examples nor the writings of many enlightened theo 
retical farmers have been able to raise it, is the passion 
for cultivating too large an extent of land, with limited 
powers as to its arrangement. Where all the land is sown 
without any portion of it being properly prepared, the 
ground is exhausted instead of being improved by cultiva- 
tion. The farmer, who takes land upon lease, has no 
interest in endeavoring to make it better, because the 
shortness of the lease does not permit him to enjoy the fruit 
of his labor ; he is forced to reap from the land all it will 
produce. 

Instead of including in his plans of cultivation a space 
of ground disproportioned to the means which are at his 
disposal, the intelligent farmer will at first occupy himself 
only with such a portion of his land as will be sufficient for 
his cattle, his manures, and his improvements ; when this 
has been brought into a good state of cultivation, and a 
regular succession of crops established upon it, he can 
carry his amendments over successive portions, till, in a few 
years, the whole soil may be brought to yield every thing 
which it is capable of producing. But it is only by long 
leases, that a farmer can be enabled to pursue a method so 
wise and so secure ; and long leases would be in all re- 
spects as much for the interest of the proprietor as of the 
farmer. 



\2d CHYMISTRY APPLIED TO AGRICULTURE. 

As the estate which T own is very extensive, I have not 
hesitated to set apart froin my regular rotation of crops, 
about two hundred and fifty acres of land of middling qual- 
ity, which had every year been manured equally with my 
best lands, but which had yielded* but poor returns. This 
great extent of land is now laid down to grass, and serves 
as a pasture for my cows, oxen, and sheep : each year I 
break up one fifth part of it, and sow it with oats, rye, or bar- 
ley, and the following year reestablish it as a grass land. I 
am convinced that this land would never have repaid me for 
the expense attendant upon raising from it successive crops 
of grain, roots, and legumes. 



CHAPTER VII. 

OF THE SUCCESSION OF CROPS. 

A SOIL may be forced, by extreme care, enormous ex- 
pense, and the use of manure without measure, to produce 
all sorts of crops ; but it is not in such sort of proceedings 
that the science of agriculture consists. Agriculture ought 
not to be considered as an object of luxury ; and whenever 
the produce of agricultural management does not amply 
repay the care and expense bestowed upon it, the system 
followed is bad. 

A good agriculturist will, in the first place, make himself 
acquainted with the nature of his soil, in order to know the 
kind of plants to which it is best adapted : this knowledge 
may be easily acquired by an acquaintance with the specie-^ 
of the plants produced upon it spontaneously, or by oxpery- 
ments made upon the land, or upon analogous soils .'n the 
neighbourhood. 

But however well adapted the soil and climate may be 
to the cultivation of any particular kind of vegetable, the 
former soon ceases to be productive, if constantly appro- 
priated to the culture of plants of the same or analogous 
species. In order that land may be cultivated success- 
fully, various kinds of vegetables must be raised upon it 
in succession, and the rotation must be conducted with 
intelligence, that none unsuited either to the soil or cli- 
mate may be introduced. It is the art of varying the 



SUCCESSION OP CROPS* 121 

crops upon the same soil, of causing different vegetables 
to succeed one another, and of understanding the effect 
of each upon the soil, that can alone establish that good 
order of succession which constitutes cropping. 

A good system of cropping is, in my opinion, the best 
guarantee of success that the farmer can have ; without 
this, all is vague, uncertain, and hazardous. In order to 
establish this good system of cropping, a degree of knowl- 
edge is necessary, which unhappily is wanting to the 
greater part of our practical farmers. I shall here state 
certain facts and principles, which may serve as guides in 
this important branch of agriculture. 

More extensive information upon this subject may be 
found in the excellent works of Messrs. Yvart and Pictet.* 

Principle 1. All plants exhaust the soil. 

Plants are supported by the earth, the juices, with which 
this is impregnated forming their principal aliment. Water 
serves as the vehicle for conveying these juices into the 
organs, or presenting them to the suckers of the roots by 
which they are absorbed ; thus the progress of vegetation 
tends constantly to impoverish the soil, and if the nutritive 
juices in it be not renewed, it will at length become per- 
fectly barren. 

A soil well furnished with manure may support several 
successive crops, but each one will be inferior to the pre- 
ceding, till the earth is completely exhausted. 

Principle 2. All plants do not exhaust the soil equally. 

Plants are nourished by air, water, and the juices con- 
tained in the soil ; but the different kinds of plants do not 
require the same kinds of nourishment in equal degrees. 
There are some that require to have their roots constantly 
in water ; others are best suited with dry soils ; and there 
are those again, that prosper only in the best and most 
richly manured land. 

The grains and the greater part of the grasses push up 
long stalks, in which the fibrous principle predominates ; 
these are garnished at the base by leaves, the dry texture 
and small surface of which do not permit them to absorb 
much (either of air or water ; the principal nourishment is 
absorbed from the ground by their roots ; their stalks fur- 
nish little or no food for animals ; so that these plants 

* '' Cours complet d' Agriculture," articles Assolement et Succession 
de Culture, par Yvart. — " Traite de Assolemens," par Ch. Pictet. 
11 



122 CHYMISTRY APPLIED TO AGRICULTURE, 

exhaust the soil, without sensibly repairing the loss, either 
by their stalks, which are cut to be applied to a particular 
use, or by their roots, which are all that remain in the 
ground, and which are dried and exhausted in completing 
the process of fructification. 

Those plants, on the contrary, that are provided with 
large, fleshy, porous, green leaves, imbibe from the atmo- 
sphere carbonic acid and wafer, and receive from the earth 
the other substances by which they are nourished. If 
these are cut green, the loss of juices which the soil has 
sustained by their growth, is less sensibly felt, as a part 
of it is compensated for by their roots. Nearly all the 
plants that are cultivated for fodder are of this kind. 

There are some plants, which, though generally raised 
for the sake of their seed, exhaust the soil less than the 
grains ; these are of the numerous family of leguminous 
plants, and which sustain a middle rank between the two 
of which I have just spoken. Their perpendicular roots 
divide the soil, and their large leaves, and thick, loose^ 
porous stalks readily absorb air and water. These parts 
preserve for a long time the juices with which they are 
impregnated, and yield them to the soil, if the plant be 
buried in it before arriving at maturity ; when this is 
done, the field is still capable of receiving and nourish- 
ing a good crop of corn. Beans produce this effect in a 
remarkable degree ; peas to a less extent. 

Generally speaking, those plants that are cut green, or 
whilst in flower, exhaust the soil but little ; till this period 
they have derived their support almost exclusively from the 
air, earth, and water ; their stalks and roots are charged 
with juices, and those parts that are left in the earth after 
mowing, will restore to it all that had been received from 
it by the plant. 

From the time when the seed begins to be formed, the 
whole system of nourishment is changed ; the plant con- 
tinues to receive nourishment for the perfecting of its 
seed, from the atmosphere and the earth, and also yields 
to the grain all the juices it had secreted in its own stalks 
and roots : by this means the stalks and roots are dried 
and exhausted. When the fruits have arrived at maturity 
the skeleton remains of the plant, if abandoned to the 
earth, restore to it only a small portion of what had been 
taken from it. 

The oleaginous seeds exhaust the soil more than the fa- 



SUCCESSION OF CROPS. 123 

nnaceous seeds ; and the agriculturist cannot be at too 
much pains to free his grounds from weeds of that nature, 
which so readily impoverish them ; especially from the 
wild mustard, sinapis arvensis, with which cultivated fields 
are so often covered. 

Principle 3. Plants of different kinds do not exhaust 
a soil in the same manner. 

The roots of plants of the same genus or family, grow 
in the soil in the same manner ; they penetrate to a simi- 
lar depth, and extend to corresponding distances, and ex- 
haust all that portion of the soil with which they come in 
contact. 

Those roots which lie nearest the surface, are more di- 
vided than those that penetrate deeply. The spindle or 
tap roots, and all those that penetrate deeply into the earth, 
throw out but few radicles near the surface, and conse- 
quently the plant is supplied with nourishment from the 
layers of soil in contact with the lower part of the root. 
Of the truth of this I have often had proof, and I will 
mention an example. If, when a beet or turnip is trans- 
planted, the lower portion of the spindle be cut off, it will 
not grow in length, but in order to obtain its supplies of 
nourishment from the soil, it will send out radicles from 
its sides, which will enable it to obtain the necessary sup- 
plies from the upper layers of the soil ; and the root will 
become roundish instead of loner. 

Plants exhaust only that portion of the soil which comes 
in contact with their roots ; and a spindle root may be able 
to draw an abundance of nourishment from land, the sur- 
face of which has been exhausted by short or creeping 
roots. 

The roots of plants of the same and of analogous spe- 
cies always take a like direction, if situated in a soil 
which allows them a free developement ; and thus they pass 
through, and are supported by, the same layers of earth. 
For this reason we seldom find trees prosper that take the 
place of others of the same species ; unless a suitable pe- 
riod has been allowed for producing the decomposition of 
the roots of the first, and thus supplying the earth with 
fresh manure. 

To prove that different kinds of plants do not exhaust 
the soil in the same manner, it is perhaps sufficient for me 
to state, that the nutrition of vegetables is not a process 
altogether mechanical ; that plants do not absorb indis- 



124 CHVMISTRY APPLIED TO AGRICULTURE. 

criminately, nor in the same proportions, all the juices and 
salts that are presented to them ; but that either vitality, 
or the conformation of their organs, exerts an influence 
over the nutritive action ; that there is on the part of 
plants some taste, some choice regarding their food, as has 
been sufficiently proved by the experiments of Messrs. 
Davy and de Saussure. It is with plants as it is with ani- 
mals, there are some elements common to all, and some 
peculiar to each kind : this is placed beyond doubt, by 
the preference given by some plants to certain salts, over 
others. 

Principle 4. All plants do not restore to the soil either 
the same quantity or the same quality of manure. 

The plants that grow upon a soil, exhaust more or less 
of its nutritive juices, but all return to it some remains, to 
repair a part of its loss. The grains and the oleaginous 
seeds may be placed at the head of those which exhaust 
a soil the most, and repair the least the injury done it. In 
those countries where plants are plucked up, they return 
nothinor to the soil that has nourished them. There are 
some plants, to be sure, besides those mentioned above, 
that by forming their seed consume a great part of the 
manure contained in the soil ; but the roots of many of 
these soften and divide the soil to a considerable depth ; 
and the leaves which fall from the stalk during the prog- 
ress of vegetation restore to the earth more than is re- 
turned by those before mentioned. There are others still, 
the roots and stalks of which remaining strong and succu- 
lent after the production of their fruits, restore to the soil 
a portion of the juices they had received from it ; of tliis 
kind are the leguminous plants. 

Many plants that are not allowed to produce seed ex- 
haust the soil but very little ; these are very valuable in 
forming a system of successive crops, as by introducing 
them into the rotation, ground may be made to yield for 
many years without the application of fresh manure ; the 
varieties of trefoil, especially clover and sainfoin, are of 
this sort. 

Principle 5. All plants do not foul the soil equally. 

It is said that a plant fouls the soil, when it facilitates or 
permits the growth of weeds, which exhaust the earth, 
weary the plant, appropriate to themselves a part of its 
nourishment, and hasten its decay. All plants not pro- 



siaccfissioN OF crops. 125 

Vided with an extensive system of large and vigorous 
leaves, calculated to cover the ground, foul the soil. 

The grains, from their slender stalks rising into the air, 
and their long, narrow leaves, easily admit into their inter- 
vals those weeds that grow upon the surface, which, being 
defended from heat and winds, grow by favor of the grain 
they injure. 

Herbaceous plants, on the contrary, which cover the 
surface of the soil with their leaves, and raise their stalks to 
only a moderate height, stifle all that endeavours to grow at 
their roots, and the earth remains clean. It must be ob- 
served, however, that this last is not the case unless the 
soil be adapted to the plants, and contain a sufficient quan- 
tity of manure to support them in a state of healthy and 
vigorous vegetation : it is for want of these favorable cir- 
cumstances that we often see these same plants languish- 
ing, and allowing the growth of less delicate herbs, which 
cause them to perish before their time. Vegetables sown 
and cultivated in furrows, as are the various roots and the 
greater part of the leguminous plants, allow room for a 
large number of weeds ; but the soil can be easily kept 
free by a frequent use of the hoe or weeding fork ; and by 
this means may be preserved rich enough for raising a 
second crop, especially if the first be not allowed to go to 
seed. 

The seeds that are committed to the ground often con- 
tain those of weeds amongst them, and too much care 
cannot be taken to avoid this : it is more frequently the 
case, however, that these are brought by the winds, depos- 
ited by water, or sown with the manure of the farm-yard. 

The carelessness of those agriculturists who allow this 
ties and other hurtful plants to remain in their fields, can- 
not be too much censured ; each year these plants produce 
new seeds, thus exhausting the land and increasing their 
own numbers, till it becomes almost impossible to free the 
soil from them. This negligence is carried by some to 
such an extent, that they will reap the grain all around the 
thistles, and leave them standing at liberty to complete 
their growth and fructification. How much better it would 
be to cut those hurtful plants before they flower, and to add 
them to the manure of the farm. From the principles 
which I have just established, we may draw the following 
conclusions, 

11* 



126 CttYMlSTllY APPLIED TO AGRICULTURE. 

1st. That however well prepared a soil may be, it cart- 
not nourish a long succession of crops without becoming 
exhausted. 

2d. Each harvest impoverishes the soil to a certain ex- 
tent, depending upon the degree of nourishment which it 
restores to the earth. 

3d. The cultivation of spindle roots ought to succeed 
that of running and superficial roots. 

4th. It is necessary to avoid returning too soon to the 
cultivation of the same or of analogous kinds of vegetables, 
in the same soil.* 

5th. It is very unwise to allow two kinds of plants, 
which admit of the ready growth of weeds among them, to 
be raised in succession. 

6th. Those plants that derive their principal support 
from the soil should not be sown, excepting when the soil is 
sufficiently provided with manure. 

7th. When the soil exhibits symptoms of exhaustion 
from successive harvests, the cultivation of those plants that 
restore most to the soil, must be resorted to. 

These principles are confirmed by experience ; they 
form the basis of a system of agriculture rich in its prod- 
ucts, but more rich in its economy, by the diminution of 
the usual quantity of labor and manure. All cultivators 
ought to be governed by them, but their application must be 
modified by the nature of soils and climates, and the par- 
ticular wants of each locality. 

To prescribe a series of successive and various harvests, 
without paying any regard to the difference of soils, would 
be to commit a great error, and to condemn the system of 
cropping in the eyes of those agriculturists, who are too 
little enlightened to think of introducing into their grounds 
the requisite changes. 

Clover and sainfoin are placed amongst the vegetables 

* In addition to the reasons I have given why plants of the same or 
analogous kinds should not be cultivated in succession upon the same 
soil, there is another which I will here assign. M. Olivier, member 
of the French Institute, has described with much care all the insects 
which devour the neck of the roots of grain ; these multiply infinitely, 
if the same or analogous kinds of plants be presented to the soil for 
several successive years ; but perish for want of food, whenever plants 
not suited to be food for their larvae, are made to succeed the grains. 
These insects belong to the family of Tipulce, or to that of flies. — 
(Sixteenth Vol. of the Memoirs of the Royal and Central Agricultural 
Society of Paris.) 



SUCCESSION OP CROPS. 127 

that ought to enter into the system of cropping, but these 
plants require a deep and not too compact soil, in order that 
their roots may fix themselves firmly. 

Flax, hemp, and corn require a good soil, and can be 
admitted as a crop only upon those lands that are fertile 
and well prepared. 

Light and dry soils cannot bear the same kind of crop as 
those that are compact and moist. 

Each kind of soil, then, requires a particular system of 
crops, and each farmer ought to establish his own upon a 
perfect knowledge of the character and properties of the 
land he cultivates. 

As in each locality the soil presents shades of differ- 
ence, more or less marked, according to the exposure, 
composition, depth of the soil, &c., the proprietor ought 
so to vary his crops, as to give to each portion of the land 
the plants for which it is best adapted ; and thus establish a 
particular rotation of crops upon the several divisions of his 
estate. 

The wants of the neighbourhood, the facility with which 
the products may be disposed of, and the comparative value 
of the various kinds of crops, should all be taken into the 
calculation of the farmer, in forming his plan of proceed- 
ings. 

In England and some of the northern countries, the cul- 
tivation of barley returns frequently in their successive 
crops, because the number of breweries afford a sure mar- 
ket for that grain. In Belgium, Russia, and upon the bor- 
ders of the Rhine, rye is generally cultivated on account of 
immense distilleries of spirit : the wants of the great num- 
bers of animals that are supplied by the malt and refuse of 
these works, gives every encouragement for the cultivation 
of that particular kind of grain. 

The cultivation of vvoad and madder would be more ad- 
vantageous in the vicinity of great manufactories, where^ 
coloring is executed, than in those countries which afford 
no consumption of these articles. In France, where the 
abundance and low price of wine will not permit us to hope 
for any market for beer ; in France, where the greatest por- 
tion of the people live principally upon bread made from 
wheat, that grain is cultivated everywhere, where it can be 
made to grow : only the inferior soils are appropriate to the 
cultivation of other grains. 

There is another point in regard to crops that ought to 



13Q CHYMISTRY APPLIED TO AGRJCULTtfftE. 

be well weighed by the farmer : though his lands may be 
suited to cultivation of a particular kind, his interests may 
not allow him to enter upon it. The more abundant any 
article is, the lower will be its price ; he ought then to 
prefer those crops of which the sale is most secure. If a 
product cannot be consumed upon the spot, it is necessary 
to calculate the expense of transporting it to a place of sale 
in countries where it is needed. 

A proprietor ought to provide largely for the wants of 
his animals and of the men living upon his estate, before 
arranging for the disposal of surplus crops : he will then 
calculate his various harvests in such a manner as to be 
always secure of receiving from the earth the means of 
subsistence for those employed in performing the labor. 

An intelligent farmer, whose lands lie at a distance from 
a market, will endeavour to avoid the expenses incident to 
the transportation of his products ; and in order to do this, 
he will give the preference to those harvests of fodder or 
of roots which may be consumed upon the place by his 
dependants and his animals. 

There is another circumstance which must be attended 
to in sowing those lands which are light, or which lie upon 
a slope ; for these it is necessary to employ such vegetables 
as cover the soil with their numerous leaves, and unite it 
in every direction by their roots, thus preserving it from 
being washed away by rains, and at the same time protect- 
ing it from being too much dried by the burning rays of 
the sun. 

In order to support by example the truth of the princi- 
ples which I have here laid down, I will make a statement 
of the series of crops that are found most advantageous in 
those countries where agriculture is the most flourishing. 
I shall commence with the provinces of ancient Flanders, 
because there the art of cultivating the soil to the greatest 
advantage had its birth. 

In the departments of Lille and Douai, where the soil is 
of the best kind, and the art of preparing and employing 
manures is carried to the greatest perfection, the following 
series of crops are adopted. 

First Series. Flax or cabbage. 
Wheat. 
Beans. 

Oats, with trefoiL 
Trefoil. 
Wheat. 



SUCCESSION OF CROPS, 129 

Second Series. Turnips. 

Oats or barley, with trefoiL 

Trefoil. 

Wheat. 
Third Series. Potatoes. 

Wheat. 

Roots, such as turnips or beets. 

Wheat. 

Buckwheat 

Beans. 

Oats and trefoiL 

Trefoil. 

Wheat 
In this rotation of crops we find that after the soil has 
been manured, the crops that are most exhausting are re- 
placed by those that are less so; and those that foul the 
soil, by those that cleanse it by requiring frequent weed- 
ings. 

It is by similar means that nearly the whole sea coast of 
Belgium, consisting of sterile sand, has been rendered as 
fertile as the best soil ; and the richest harvests have followed 
from a judicious system of cropping. 

Upon the sands in the neighbourhood of Bruges, Ostend, 
Nieuport, Arvens, &c., the cultivation of the grains is made 
to alternate advantageously with that of beans, cabbage, 
potatoes, and carrots. The system of cropping practised in 
Norfolk, anti so much praised by the English, consists in 
commencing the series by the cultivation of roots in a well 
manured soil; these are followed by oats or barley with 
trefoil, and afterwards by wheat 

In the bed of dry sand which forms the soil of Cam- 
pine, the industrious inhabitants have with equal success 
vanquished all obstacles, and fertilized the soil. It is sur- 
prising to find in these plains of sand, excellent crops, 
which, by their judicious arrangement, are constantly ame- 
liorating the soil. The series which is there followed is 
this. 

Potatoes. 

Oats and trefoiL 

TrefoiL 

Rye. 

Turnips 
During a tour which I made with Napoleon in Belgium, 
I heard him express to one of the council of a department. 



130 CHYMISTRY APPLIED TO AGRICULTURE. 

his surprise at the vast extent of waste land over u^hich he 
had just travelled : he was answered thus ; " Give us a 
canal to transport our manures, and to convey away our 
produce, and in five years this sterile country will be covered 
with crops." The canal was afterwards constructed, and 
the promise realized in less than the required time. 

In the interior of France, where cattle subsist almost 
entirely upon fodder, and are not, as in the northern coun- 
tries, fed upon the mash from breweries and distilleries, 
crops of the various plants used for their support should be 
more extensively cultivated, and should occur more fre- 
quently in the rotations. 

In all the compact and slightly argillaceous soils upon 
my estates, if they are deep, after having had them well 
dressed with barn-yard manure, I commence my series of 
crops with beets, to which succeeds wheat, which I sow 
immediately after having drawn the beets, and without any 
intermediate tilling ; the wheat I replace by artificial 
grasses, and these by oats. When the land is of very good 
quality, I follow wheat by clover, and this in its turn is 
succeeded by the grains, and by roots. 

In light soils, which are deep and sandy but fresh, such 
as those upon the borders of the Loire, which are sub- 
merged once or twice every winter, I sow, first, winter 
vetches, which produce abundantly, and these I replace by 
beets. 

Independently of the use which I have for beets in my 
sugar manufactory, I believe this plant may be cultivated as 
food for cattle, more advantageously than any other. The 
leaves of those that have completed their growth, may be 
used as food for animals during the months of August and 
September ; and the roots supply a quantity of nourishment 
of from twenty to thirty thousand weight per acre, or more 
than forty thousand per hectare. 

Lands of the best kind, that is to say, lands which, to a 
good mixture and sufficient depth, unite a favorable ex- 
posure and suitable manures, may receive into their series 
of crops all the plants adapted to the climate ; but there are 
not many soils possessing all these qualities. 

In the siliceous, and calcareous soils, as they are gener- 
ally dry, may be alternated crops of rye, barley, and white 
rye, with those of sainfoin, lupines, lentils, French beans, 
chick peas, radishes, woad, buckwheat, potatoes, &/C. 

Preference ?honM ??'wiys be given to those crops which 



PRODUCTS OF FRENCH AGRICULTURE* 131 

experience has declared to be best suited to the soil and 
climate, as well as to those of which the products are the 
most advantageous to the proprietor. 

In compact lands, containing a portion of clay, and 
which from their quality are suitable for wheat, the succes- 
sive crops may consist of wheat, oats, trefoil, clover, vetch- 
es, beans, turnips, radishes, cabbages, mustard, &c. A 
succession or rotation of crops should be established in 
these various soils, according to the principles which I 
have explained. 

A succession of crops well conducted, economizes labor, 
manure, expense of transportation, &c. : it furnishes the 
means of raising and fattening a greater number of ani- 
mals, and it ameliorates the soil to such a degree as en- 
*irely to change its nature ; so that the most delicate plants, 
and those requiring the most nourishment, may be raised 
in a soil originally sterile and ungrateful. The arid sands 
of Belgium, and many of the alluvions on the borders of 
our great rivers, offer numerous examples of the truth of 
this. A good system of cropping alone can give security 
of a lasting prosperity in agriculture. 



CHAPTER Vm. 

VIEW OF THE PRODUCTS OF FRENCH AGRICULTURE. 

A REGISTER of the products of French agriculture, made 
with great care from 1800 till 1812, gives as the mean 
result of these twelve years,* 

1. Wheat 51,500,200 hectolitres.t 

2. Rye and meslin (meteil) . 30,290,161 

3. Indian corn 6,302,316 

4. Buckwheat 8,509,473 

5. Barley 12,576,503 

6. Dry pulse 1,798,616 

* For the details relative to the various products here united in a 
tabular form, the reader may consult my Treatise on French Industry, 
He will there find, not only the observations and the data which were 
deemed necessary to establish these results, but also the valuation and 
estimate of all these products in money. 

[t The hectolitre is equivalent to 22.009667 gallons. — Tk.] 



13^ 



CHYMISTRY APPLIED f ^ iRlCVLTVRE^ 



7. Potatoes . . . 

8. Oats . . . , 

9. Small grains . . 

10. Wines . . . . 

r merino 

11. Wool J halflbreed 

( common . 



19,800,741 bectolitrejiv 
32,066,587 

1,103,177 
35,358,890 
790,175 ) . ., 

3,901,881 ^^^^^T" 
33,236,487 ) "™^^' 



Total 37,928,543 kilogr, 

12. Cocoons of silk .... 5,157,609 kilogr, 

13. Hemp and flax .... 49,677,300 

14. Oils of all kinds .... 130,000,000 
Independently of the principal products of French agri- 
culture above enumerated, there are several distinct crops,^ 
which, without presenting such large results, enrich cer- 
tain localities: as, for example, madder, saffron, hops, 
woad, fruits, green pulse, &c. 

I think it proper to add to the above table^ that of the 
animals which are more ox less employed in agriculture. 

1. Oxen 1,701,740 

2. Bulls 214,131 

3. Cows 3,909,959 

4. Heifers 856,122 

5. Horses or mules . . . 1,406,671 

6. Colts ..,.., 464,659 

7. Pure merino sheep . . 766,310 

8. Half-breed merino sheep 3,578,748 

9. Common sheep . . 30,845,852 
10. Swine ..... 3,900,000 



CHAPTER IX. 



OP THE NATURE AND USES OF THE PRODUCTS OF 
VEGETATION. 

The elements that enter into the composition of plants, 
are but few in number ; but the proportions in which they 
are combined establish so great a difference in the prod- 
ucts of vegetation, that it seems almost incredible, that 



r* The kilogramme is equivalent to 2.20548 lbs. avoirdupois. — Tr.] 



NATURE AND USES OF PRODUCTS. 133 

these should be the effect of so small a number of princi- 
ples, varying only in the proportions in which they are 
united. 

The aliments of plants are water, air and manures : 
these substances absorbed by the leaves, the fruits, or the 
roots, furnish by analysis, carbonic acid, hydrogen, a lit- 
tle azote, and some earthy and saline principles : it is 
from these materials that the almost endless variety of 
widely differing products of plants is formed by their or- 
gans. 

During the progress of vegetation these products are 
found to undergo successive changes; that which is first 
acid becomes sweet ; that which is tender becomes hard, 
and all is owing wholly to the constant changes taking 
place in the proportions of the constituent principles ; and 
one is astonished at finding that the most exact analysis of 
substances possessing the most opposite characteristics, 
detects no other difference than some hundredths more or 
less in the proportions of their elements. 

When a plant has completed or terminated its various 
stages of vegetation, the dead remains, if exposed to the 
action of the same agents, such as air, water, and heat, 
suffer a succession of retrograde changes ; they are grad- 
ually decomposed, and their constituent principles enter 
into combination with those of the bodies by which they 
are acted upon ; thus the dead plant is entirely governed 
by those invariable physical and chymical laws, which in 
the living plant are governed and modified by the laws of 
vitality, the action of which regulates that of all external 
agents, and produces results which we can neither explain 
nor imitate. 

Though great caution should be used when endeavouring 
to establish an analogy between two modes of existence 
differing so widely as those of animals and vegetables, it 
must be perceived that there is a resemblance in the manner 
in which both are nourished. 

Animals inhale air by their lungs, or absorb it by glands 
scattered over their bodies ; they are nourished by solid 
aliments received into their stomachs, or into some analo- 
gous organ : plants absorb air by their leaves and fi-uits, and 
imbibe through their roots the nutritive juices contained in 
the earth. In animals, the juices circulate through every 
part, and pass into all the various organs, in which they are 
elaborated, in order to form all the products which belong 
12 



134 CHYMISTRY APPLIED TO AGRICULTURE, 

to this kingdom : in vegetables the juices are carried into 
the bark, the alburnum, the pith, the wood, the leaves 
and the fruit, by tubes and glands, which are arranged in 
hexagonal cells, and are very numerous in the parenchyma, 
and in the cortical layers of the bark : the juices undergo 
particular modifications in the various organs, and form in 
each one of them new compounds differing from each 
other. 

The leaves receive the sap in vessels of the most delicate 
texture ; in these it is elaborated, and combined with sub- 
stances absorbed from the atmosphere, whilst the surplus of 
vtrater, as well as the oxygen of the carbonic acid from 
which they have extracted the carbon, is given out by the 
leaves through their transpiring pores. The sap, after ex- 
periencing these changes, passes into the organs of the 
plant, where it is subjected to new elaborations. 

The leaves are to plants what the lungs are to animals ; 
those receiving the sap, as these do the blood, to be mingled 
in them with the gas absorbed from the atmosphere, and to 
pass thence into the great vascular system ; and from both 
leaves and lungs the superfluous water and gases are thrown 
out into the air. 

We likewise find a great variety of structure amongst 
the various species of which the two kingdoms are com- 
posed; some have a soft, loose, parenchymatous formation; 
others present a harder and dryer tissue; this, in vegetables, 
is owing to the predominance of carbon ; in animals, to thai 
of phosphate of lime ; these two principles, though very 
different, form the basis of their separate structures. The 
same elements enter into the composition of all the products, 
whether animal or vegetable ; the difference between them 
arising solely frojaa the different proportions of the constitu- 
ent principles. 

An analysis of the principal products of vegetation has 
been made with great care by JVIessrs. Gay-Lussac and 
Thenard. The results of these researches enable us already 
to draw some conclusions in regard to the character of any 
one of the products, according as this or that principle ma) 
predominate in its composition ; or according to the nature 
of the elements combining to form it. Thus we know, 

1. That a vegetable substance is acid when it contains 
no azote, and when the quantity of oxygen in proportion to 
that of hydrogen, is greater than is necessary for the forma 
ion of water 



GUM AND MUCILAGE. 13-'> 

2. That when the proportion of hydrogen to that of o» 
ygen is greater than is necessary for the formation of water, 
the substance is oily, resinous, a'.coholic, or ethereal. 

3. That when the quantity of oxygen and hydrogen con- 
tained in a substance is the same as in water, the substance 
is analogous to sugar, gum, fibre, &;c. 

I shall in this work speak only of such products of vege- 
tables as are most common, or of the most extensive use, 
either for domestic purposes, or in the arts ; and I shall 
endeavour as much as possible to follow the order prescribed 
by the analogy of their constituent principles. 



ARTICLE L 

€rum and Mucilage. 

Mucilage appears to be in the greater part of vegetables 
the effect of the first change wrought upon the sap by the 
laws of vitality; and the gums, which differ so little from it, 
are generally formed upon trees by the extravasation of the 
sap, during the period of most vigorous vegetation. This 
first product of vegetation appears, however, to be perma- 
nent through all its stages: the leaves of the marsh mallows, 
the seeds of flax, lichens, and the bulbs of hyacmths fur- 
nish it at all times ; so that it appears to be a constant and 
inherent product of their composition. 

Gum exists in a liquid form in the cells of plants; it 
hardens by exposure to the air, loses a portion of its trans- 
parency, experiences a greater or less change of color, and 
becomes slightly brittle. Mucilage preserves its consistency 
a longer time, though it has less affinity for water 

Gum and mucilage are soluble in water, from which they 
may be precipitated by alcohol, and by sulphuric acid : they 
burn with difficulty, and during ignition give out but little 
flame, and produce a great deal of smoke; their residuum 
consists of bubbles of carbon. 

The gums that are most used in the arts, are gum Ara« 
bic, gum Senegal, and the reddish gum of the country, 
which forms in tears upon the branches and trunks of plum, 
cherry, apricot, and many other trees. 

Gum and mucilage may be employed as food : mucilage 



136 CHYMISTRY APPLIED TO AGRICULTURE. 

is sometimes prescribed in medicine as a mild, soothing, 
and easily digested article of nourishment. 

The use of gum in the arts is very extensive ; it is used 
in preparing cloths and felt for receiving a gloss ; writing- 
paper is covered with a thin coating of it to prevent the 
ink from spreading. Gum is used as a receiver of the 
colors, which are applied by impression to cloths of all 
kinds : the use of it in stamping cotton and linen goods is 
now superseded in England by that of mucilage extracted 
from lichens. 

The specific gravity of the gums is from 1300 to 1490, 
water being 1000. Messrs. Gay-Lussac and Thenard found 
gum Arabic to contain 

Carbon 42.23 

Oxygen 50.84 

Hydrogen 6.93 

Oxygen and hydrogen are found in it in the proportions 
necessary for forming water. 



ARTICLE II. 

Starch or Fecula. 

Starch is a white, finely divided, pulverulent substance, 
insoluble in cold water, and forming a glue in boiling 
water. When this substance is obtained from any other 
plant than one of the grains, as from potatoes, corn-flag, 
bryony, horse-chestnut, male orchis, dog-bane, burdock, 
iris, hen-bane, patience, ranunculus, &c., it is known by 
the name of fecula. 

In many parts of America the principal food of the 
inhabitants is procured from the fecula of the manioc. 
The preparation of sago from the pith of old palm trees, 
and of salep from the bulbs of all the varieties of orchis, 
shows the important purposes which may be answered by 
the fecula of various plants, in the arts, in medicine, and 
as nourishment for the human species and for animals. 
The fecula contained in all the plants I have just named 
is wholesome, and very nourishing, and may be used as 
food in various forms ; but it is necessary to keep in mind, 
that in most of these vegetables it is combined with other 



STARCH OR FECULA. 137 

substances either actually poisonous, or possessing a sharp, 
bitter, acrid, or otherwise disagreeable taste : it is there- 
fore of the greatest consequence that the fecula should be 
prepared from them with the utmost attention to freeing 
it from every other portion of the plant. Fortunately the 
nature of the substances which are united with the fecula 
is so different from that of the fecula itself, and the char- 
acteristics of each are so distinct, and so well marked, 
that they can be separated from each other by a process 
equally easy and sure. The great solubility in water of 
all the injurious principles, and their extreme levity when 
compared with the weight of the fecula, causes them, when 
exposed to repeated washings, to rise to the top of the 
vessel in which the operation is performed, whilst the 
fecula, freed from any mixture, remains at the bottom. 

Two processes are employed for extracting fecula ; both 
must be commenced by reducing to a state of fine division 
the substance containing it. The fecula is afterwards 
obtained either by means of cold water alone, or by fer- 
mentation. The first of these methods is the most simple 
and expeditious, but by it all the fecula is not obtained; 
the second, therefore, though longer and more expensive 
is preferred for extracting starch from the grains. 

When starch is to be extracted by cold water, the sub- 
stance must either be reduced to the state of flour, or be 
broken so that the pulp can be acted upon by the water. 

In the first case, the flour of wheat is kneaded with 
water, till it takes the consistency of a stiff paste ; this is 
placed on a cloth stretched tightly over a tub, and cold 
water thrown upon it ; the kneading with the hand is 
continued till the water runs off clear ; the fecula is car- 
ried off by the water and deposited at the bottom of the 
tub ; the water retains in solution the sugar and the ex- 
tractive matter of the farina, whilst the insoluble gluten 
alone remains upon the filter ; the deposit is washed to 
free it from any foreign substance, and then dried. When 
it is not wished that the substance containing the fecula 
should be reduced to flour, it may be broken in a mortar, 
or under a mill-stone, or it may be grated ; the pulp is then 
to be placed upon a very fine horse-hair sieve, and water 
thrown upon it till it runs off clear; care being taken to 
stir the pulp constantly with the hand and to squeeze it 
hard. 

When the substance from which the fecula is to be e/« 
12* 



138 CHYMISTRY APPLIED TO AGRICULTURE. 

tracted is fleshy, and of a loose, spongy texture, it can be 
reduced to a pulp by means of a press; the juice thus 
expressed deposits the fecula, which must be very carefully 
washed, in order that the noxious principles contained in 
it may be perfectly separated. The whiteness and ex- 
cellence of the fecula depends upon its being thoroughly 
washed. 

Fermentation is the means most commonly employed 
for extracting starch from grain ; but this operation will 
produce only alcohol, if care be not taken in mixing the 
acid with the grain to prevent the spirituous fermentation. 
This acid is made by mixing with a bucket of hot water 
two pounds of baker's yeast, to which is added, two days 
after, several buckets of hot water ; in forty-eight hours 
from that time the acid will be sufficiently developed. 

This acid, which is called by the starch manufacturers 
sure water, contains nothing but vinegar, and I therefore 
presume, that the acetic acid may be used with the same 
success. 

In order to extract the starch by fermentation, a bucket 
of this sure water is thrown into a hogshead having one 
end taken out. The hogshead is then filled half full of 
common water, into which flour is stirred till it is full ; 
the whole is then left to macerate during ten days in 
summer, and fourteen in winter. The sufficiently ad- 
vanced state of the maceration may be known by a de- 
posit being formed, and the liquor swimming above it re- 
maining clear, whilst the surface is covered with foam or 
fat loater. The water and foam is drawn off, and the 
deposit is thrown into a sack of hair-cloth, which is placed 
in a tub, and water thrown over it till it runs off without 
any cloudiness. The substance remaining in the bag, 
which is only the coarsest part, serves as food for cattle. 
At the end of two or three days, the water floating above 
the deposit formed in the tub is drawn off, and a part of it 
preserved to serve as sure water, for succeeding operations. 

In order to have good starch, the deposit must be wash- 
ed in a great deal of water and well mixed ; two or three 
days after, the water for the remaining washings may be 
thrown on. 

The deposit which is formed presents three layers differ- 
ing widely in their quality ; the first is principally com- 
posed of fragments, and is taken off as food for cattle, or 
to fatten hogs with. The second layer is generally formed 



STARCH OR FECULA. 1^9 

of the mealy part of the vegetable mixed with some other 
substances: the product of this layer is known under the 
name of common starch. 

The third layer contains the purest and heaviest starch ; 
but in order to give it all the qualities it ought to possess, 
it must be washed with water, and the water afterwards sep- 
arated from it by filtration through a sieve of silk, so as to 
free it from all impurities. With these precautions starch 
may be obtained fitted for any use. 

As soon as the starch has been well washed, it is put into 
baskets lined with linen, to be well drained. It is afterwards 
divided into loaves, and the drying finished by exposing it 
in the open air upon laths. Before packing for sale, the sur- 
face of the loaves, which is slightly colored, is scraped, and 
the drying of them is completed in the sun or in a stove. 

The use of starch and of fecula is very extensive ; starch 
mixed with boiling water, takes the consistency of jelly, and 
forms size ; when tinged with blue, it is used for giving a 
gloss and stiffness to linen ; when reduced to a fine powder, 
it is used for dressing the hair. Fecula forms the basis of 
the greater part of our food, and is in itself an excellent 
article of nourishment. 

Starch acted upon by sulphuric acid is converted into 
sugar, and in this state may be made to undergo the vinous 
fermentation. A few years since extensive establishments 
were formed in France, for supplying numerous distilleries 
with the fecula of the potato, which had been treated in 
this manner. 

Starch thrown upon red-hot iron, burns, leaving scarcely 
any residuum. 

Messrs. Gay-Lussac and Thenard have found that 100 
parts of starch contain 

Carbon 43.55 

Oxygen 49.68 

Hydrogen 6.77 

So that in starch, as in gum and mucilage, oxygen and 
hydrogen are combined in the same proportions as in water; 
and those substances resemble starch in their characteristics, 
and in their uses. 



140 CHYMISTRY APPLIED TO AGRICULTURJE. 

ARTICLE III. 

Sugar, 

Sugar is a substance of a sweel and agreeable taste 
which is extracted from certain vegetables : it is light 
colored, and when dissolved in water to which a little 
yeast has been added, is capable of undergoing the vinous 
fermentation. All those substances that experience the 
same fermentation by the same means, contain more or 
less sugar. The same characteristic may be bestowed by 
art upon many other products of vegetation, causing them 
to vary, by chymical processes, the proportions of their 
constituents, till they approach those of sugar; it is in 
this way that starch and vegetable fibre may be made to 
undergo the vinous fermentation. All those substances 
that possess the property of forming the vinous fermentation, 
may be called by the general name of sugar. There are 
three kinds of sugar, the characteristics of which are very 
distinct ; the first and most important is that which crystal- 
lizes, and to which the generic name of sugar is given ; 
this is furnished by the sugar cane, the beet, carrot, turnip, 
chestnut, maple, &c. 

The sugars procured from these different plants, are, 
strictly speaking, of the same nature, and do not, when 
brought by the process of refining to the same degree of 
purity, differ in any way from each other : their taste, man- 
ner of crystallization, color, and weight are then precisely 
the same, and no person, however much in the habit of 
judging of these products, or of consuming them, can dis- 
tinguish one from the other. 

The second kind of sugar, is that which is extracted 
from the must of grapes; this always appears in the form 
of a white powder, in which no trace of crystallization can 
be found ; it possesses the properties of the first kind of 
sugar, and provided a double portion of it be used, an- 
swers the same purposes. During the time when American 
sugar was scarce, and consequently excessively dear in 
France, an enormous quantity of grape sugar was manufac- 
tured and sold at a low price. 

The third kind of sugar, is that which is contained in 
nearly all fruits ; this not only refuses to crystallize, but 
cannot be made to assume solid form. The juices cf 



WAX. 141 

these fruits may be reduced to a sirup supplying for many 
purposes the place of sugar, and of great use as an article 
of food. By concentrating these nutritive substances, the 
advantage of reducing them to a small bulk is added to 
that of preserving them from decomposition : the same 
effects are produced by concentrating them to a jelly or 
an extract. Those sweet juices, that are not convertible 
into sirups, will, by being fermented, form a vinous liquor, 
equally useful, healthful, and agreeable, to a great portion 
of the people. 

Those substances, which are, by the aid of chymistry, 
convertible into sugar, furnish only the second kind of it ; 
this is very suitable for being made by fermentation to 
produce alcohol. 

The specific gravity of sugar is, according to Fahren- 
heit, 1.6 ; it dissolves in its own weight of water, at the 
temperature of 50°. Sugar contains 42.47 per cent, of 
carbon ; hydrogen and oxygen are found in it as in the 
gums, in the same proportions as in water. 



ARTICLE IV. 

Wax. 

Though wax can be extracted in considerable quanti- 
ties only from the berries of the myrica cerifera, yet it is 
contained in nearly all plants ; it exists in greater or less 
quantities in the leaves o most trees. Wax is also formed 
by the decomposition ot several roots; for if, when the 
first operations are performed for extracting sugar from 
the juice of beets, they be not well conducted, from the 
moment the boiling of tne concentrated sirup, in order to 
form the sugar, is commenced, there collects upon the 
surface a thick, whitish, glutinous substance, which, when 
removed with the skimmer and dried, exhibits all the 
characteristics of wax ; it is insoluble either in water or 
alcohol ;. it burns like wax, and has the same consistency ; 
nor does it in any other respect differ from it. It is this 
substance that adheres to the sides of the boilers when 
^he sirups have become thickened by boiiiu^, beyond 35" 
of the aerometer of Bauroe. The burning of the liquor, 



142 CHYMISTRY APPLIED TO AGRICULTURE. 

which prevents the ebullition from being carried to a 
sufficient extent to produce a good crystallization of the 
sugar, is caused by this substance. There cannot be too 
much care taken in the first operations to prevent this 
deterioration of the sirup, as this alone has occasioned 
the failure of most of the establishments, which were 
formed in France in 1810, for manufacturing sugar from 
beets. 

Nearly all the wax which is used in the arts, and for 
domestic purposes, is produced by bees, the cells of their 
hives being formed by it. This wax is found in scales or 
plates under the abdomen of the insect, and appears to be 
a transudation, which becomes thickened, and which the 
bee detaches by rubbing, to form his cells. 

Wax is bleached by pouring it when melted upon a 
cylinder partly immersed in water, and to which a rapid 
rotatory motion is given. The wax, as it flows over the 
moistened surface of the cylinder, congeals in very thin 
layers, which are afterwards exposed upon cloths in the 
sun for some time, that they may acquire a clear white- 
ness. 

It does not appear, that in the elaboration of wax, the 
bee bestows upon it any animal character whatever , the 
wax which is furnished by bees is precisely of the same 
nature as that procured directly from some vegetables. 
Wasps build cells, which they use for the same purposes 
as the bees do theirs ; but the materials of which they are 
constructed is ligneous, and consists of minute portions of 
the fibrous part of vegetables cemented by an animal glut?*!. 
According to the analysis of Messrs. Gay-Lussac and The- 
nard, 100 parts of wax are composed of 

Carbon 81.784 

Oxygen ...... 5.544 

Hydrogen 12.672 

The property possessed by wax, of burning without pro- 
ducing either odor or smoke, has caused it to be generally 
used for lighting the apartments of the wealthy : tallow 
and the common oils have always been used by the poor, 
and they are so even at this day, when science and chymis* 
try have united to perfect the mode of lighting by oil. 



OILS. 143 

ARTICLE V. 

Oils* 

The oils are fat, unctuous bodies, of various degrees of 
fluidity, insoluble in water, forming soap with the alka- 
lies, and burning and evaporating at different tempera- 
tures. It is the last characteristic, particularly, which es- 
tablishes that difference amongst them by which they are 
divided into fixed and volatile oils. The fixed oils are 
contained in seeds and fruits, from which they are ex- 
tracted by pressure. The first portion which is expressed 
is the purest, and is known by the name of virgin oil ; 
that which follows is rendered more or less impure by the 
mixture of other principles contained in the fruit submit- 
ted to compression. It is particularly by the mucilage, 
which is found in a greater or less quantity in all vegetables, 
that the purity of oil is affected. 

After all the oil, which can be extracted by pressure, 
has been drawn off, it is customary to moisten the mash 
with boiling water, and to subject it to another and more 
powerful pressure ; but the oil thus obtained carries with 

^ I make use of the generic term oil, by which two substances, 
differing widely from each other, have been for a long time known ; 
but I ought to observe, that the properties which are common to 
them, are not sufficient to authorize their being included under one 
name, and that in all their relations they present so great a difference 
as to entitle them to be considered as two kinds of products, and to be 
designated by specific names. 

1. The fixed oils are insoluble in alcohol; the volatile oils are 
soluble. 

2. The fixed oils have generally neither odor nor flavor ; the vola- 
tile oils are pungent, caustic, and very odoriferous. 

3. The property of burning, common to the two oils, belongs like- 
wise to all vegetable substances properly so called. 

4. The fixed oils are obtained only from seeds and fruits ; many 
volatile oils are extracted from all parts of plants. 

5. The fixed oils are for the most part employed as food ; the vola- 
tile oils are useful only in the arts. 

6. The fixed oils evaporate only at a high degree of temperature ; 
the volatile oils are dissipated entirely at the temperature of the 
atmosphere. 

7. The characteristic of forming soap does not belong exclusively 
to the oils ; it is possessed by many other substances, animal and 
vegetable. 

Thus what are called volatile oils are only liquid or concrete 
aromas, and it is in the class of aromas that they ought to be ranked, 



144 CHYMISTRY APPLIED TO AGRICULTURE. 

it a large portion of mucilage, and is usually employed only 
in some of the trades. In some countries it is customary 
to collect the fruits into heaps, and to subject them to a 
degree of fermentation before pressure; by this means the 
extraction of the oil is rendered easier, and the quantity of it 
is increased, but the quality of it is much injured. Similar 
results are obtained by breaking the fruit previous to ex- 
pressing the oil. 

It would be hardly right to condemn these last methods 
as erroneous, because in the numerous soap-works, dye- 
houses, cloth manufactories, &c., this quality of oil is 
preferred to that which is purer. The learned will do 
well to condemn the processes now employed for procur- 
ing the fine oils, and to prescribe others by which we may 
obtain them purer and of a better taste ; but the grand 
consumption of the oils is in the manufactories, and there 
the fine oils would very imperfectly replace those of a 
coarser kind ; thus, by perfecting the produce, the useful- 
ness of it would be lessened. When oil is to be extracted 
for domestic purposes, it is without doubt desirable that it 
be obtained as pure as possible ; but that which is destined 
to be employed in the trades, and in manufactures, as in 
that of soap for instance, is the better for being combined 
with a portion of mucilage. The great art of manufactur- 
ing consists in appropriating the products to the wants and 
tastes of consumers. 

When mucilage is so abundant in an oily seed, that it 
yields upon expression only a pasty combination of muci- 
lage and oil, the seed is dried by fire : when the mucilage 
is thus deprived of fluidity, the oil flows off* pure. In this 
manner the seeds of flax, of poppies, of hen-bane, &lc. are 
prepared for expression. 

Nearly all oils are colored, and contain some of the 
principles of the fruits from which they are procured ; these 
are in some of their effects injurious to the oil, and great 
pains has been taken to find some means of freeing it from 
them. Oil is clarified to a certain degree merely by stand- 
ing in a cool place in open earthen vessels ; it forms a 
deposit and is thus rendered purer, clearer, and better. If 
oil is exposed to the sun it gradually loses its color. 

In order to clarify the oil of mustard, one per cent, of 
sulphuric acid is put into a large earthen pan, into which 
the oil is thrown and carefully stirred: the oil becomes 
green, and upon being allowed to remain at rest, forms 



OILS. 145 

upon the sides and bottom of the pan a blackish deposit, 
which is principally composed of carbon : the process 
must be repeated after a few days, if the oil have not ac- 
quired the wished for clearness. Before using the oil, it is 
necessary that it should be allowed to remain for some 
time undisturbed. In this operation the mucilage appears 
to be precipitated and consumed by the acid. Most fixed 
oils contain some mucilage, and most of them become 
rancid. 

Most fixed oils have but in a very slight degree the 
property of drying ; but some of them acquire it by being 
combined with some metallic oxide, and this greatly in- 
creases the use of them, as they can in this way be em- 
ployed as varnishes for covering bodies which it is neces- 
sary to preserve from air and water ; or as the recipients 
of colors to be used in painting upon cloth, wood, or metal. 
The best drying oils are those of flaxseed, nuts, and poppies. 
Linseed oil will dissolve at boiling temperature -^ of its 
weight of that oxide of lead known in commerce by the 
name of litharge. It becomes brown in proportion as the 
oxide is dissolved : when saturated with the oxide it thick- 
ens by cooling, and it is necessary to render it liquid by 
heat at the time of using it. Linseed oil, saturated with the 
oxide and applied with a brush to any substance, hardens 
readily and forms a coating impervious by water, and 
much resembling gum elastic ; linen or silk prepared with 
it is flexible without being adhesive. 

A cement of this oil prepared with the oxide, and mixed 
with the refuse or broken fragments of porcelain or of well 
baked potter's ware, is used with great success in uniting 
the tiles upon roofs, and in cisterns, and reservoirs. To 
form this cement the pulverized fragments are thoroughly 
incorporated with the heated oil, and applied by the trowel 
whilst in that state. 

When linseed oil is to be used in painting, ^ or at the 
most yV P^''^ of litharge is sufficient to render it drying. 

In consequence of the numerous purposes to which the 
fixed oils are applied, the consumption of them is im- 
mense : they form the basis of the soaps, both soft and 
hard, according as they are combined with potash or soda : 
they are used to fix in the most durable manner upon cot- 
ton the colors obtained from madder : they are employed 
to facilitate the operations in all establishments for card- 
ing and spinning wool. It is by the use of oil that the play 
13 



146 CHYMISTRY APPLIED TO AGRICULTUKE. 

of all machinery is rendered more regular and easy, and 
that friction is moderated j and by it metals are pre- 
served from rusting. 

The most important use to which oil has been applied is 
that of lighting buildings ; but as it gives out, in burning, 
more or less smoke, and a light inferior in brilliancy to 
that of vi^ax, the latter was preferred until the invention of 
Argand's lamps : in these a current of air passes rapidly 
through a circular wick surmounted by a cylindrical glass, 
and thus the smoke is consumed and the light rendered 
more clear and brilliant. 

The products of the combustion of the fixed oils are 
water and carbonic acid ; this declares their constituent 
principles to be carbon, oxygen, and hydrogen. Messrs. 
Gay-Lussac and Thenard have found them in the follow- 
ing proportions. 

Carbon 77.213 

Oxygen 9.427 

Hydrogen 15.360 

The volatile or essential oils are more easily volatilized 
than the fixed oils ; they are inflammable at a lower tem- 
perature, are soluble in alcohol, exhale a powerful odor by 
which they are distinguishable from each other, and have 
a lively, acrid, and burning taste. 

The volatile oils do not belong exclusively to any one 
part of plants : in some, as in the Bohemian Angelica, the 
oil is distributed throughout the whole plant : sometimes, 
as in balm, mint, and wormwood, it is found in the leaves 
and stalks : the elecampane, Florence iris, and bennet 
contain it in their roots ; thyme and rosemary in their 
leaves and flower buds ; lavender and the rose in their 
calyces; camomile, lemon, and orange plants, in their 
flowers ; the petals, and the rind of the fruit of the two 
last abound in oil ; that of indigo and fennel is contained 
in vessels forming the raised lines which may be perceived 
on the bark. 

Volatile oils vary in color, consistency, and weight : 
there are some, as that of sassafras, and the clove, for in- 
stance, which are heavier than water ; and there are some, 
as those of the rose and parsley, that remain in a concrete 
state at the usual temperature of the air, &.c. 

The volatile oils are extracted either by distillation or 
expression. When the oil is contained in vesicles upon 
the surface of the rind, as is that of the lemon and berga- 



RESIN. 147 

mot, the cells may be broken and the oil caused to flow 
out by merely rubbing the rinds together ; or, the rinds 
may be taken off by grating, and the oil separated from the 
pulp by a light pressure, or by allowing the whole to remain 
undisturbed for a few days, when the pulp will settle at the 
bottom, and the oil remain floating above it. 

When these rinds are scraped with a bit of sugar, the oil 
combines with it, forming an oleosaccharum, useful in giving 
a pleasant flavor to liquors. 

With the exception of the oils of which I have just 
spoken, all the volatile oils are extracted by distillation : 
in this process the plant is put into the boiler of the alembic, 
and covered with water ; when the water boils the oil rises 
with the steam, and is condensed with that in the 
worm of the still, whence they flow together into the 
receiver : the oil which swims upon the top is separated 
from the water, and this water, which has a milky appear- 
ance, is again employed from preference in new distilla- 
tions. 

It is customary to make use of a narrow, straight-necked 
vessel as a receiver : the oil collects in the upper part ot 
this, whilst the water passes off through a siphon in the 
side, about four inches below the neck. 

In the south of Europe, where great quantities of the 
volatile oils are prepared, the distillers place their portable 
apparatus in the open air, in those places which offer a plen- 
tiful harvest of aromatic plants ; when these are exhausted 
they remove elsewhere. 

The aromatic oils are employed particularly as perfumes, 
and for this purpose are often combined with other sub- 
stances. They are likewise used in the manufacture of 
varnishes, from the readiness with which they dissolve 
colors, and from their quick evaporation after being ap- 
plied. 



ARTICLE VI. 

Resin. 

The occurrence of resin is very common throughout the 
whole vegetable kingdom, but it is from those trees which 



148 CHYMISTRY APPLIED TO AGRICULTURE. 

are most numerous, as pines, cedars, &.c. that it is princi- 
pally extracted, and the terra resinous is applied to them 
from the very great proportion of resin contained in their 
sap. 

The mode of collecting resin is by cutting notches 
through the bark of the trunks of resinous trees near the 
base, at that season when the sap, softened by the return- 
ing warmth of spring, begins to rise in the vessels. As 
resin abounds principally in the alburnum, the notches 
must be of sufficient depth to pass through that ; the in- 
cisions must be enlarged or renewed, once in fifteen days. 
The flow of the resin ceases as the return of frost causes 
the vessels of the trees to contract. A healthy and well- 
grown tree will furnish from twelve to fifteen lbs. of resin 
per annum. 

A different process is made use of in extracting resin 
from dead trees ; the bark and young branches of these 
are taken off, and the remainder reduced to small pieces 
which are piled up in a heap and covered over, excepting a 
small opening which is left at the top : the heat of the fire 
which is kindled at the upper part is sufficient to melt the 
resin which flows down to the bottom, and is carried off by 
channels, into vessels prepared to receive it. 

This reiin is black, and contains a great quantity of 
pyroligneous acid and volatile oil : it is known in commerce 
under the name of tar;* the quality of it varies according 
to the care with which it is extracted : if the heat be too 
great, the volatile oil is thrown off, and the resin rendered 
dry and brittle : it cracks when used, and renders the 
substances to which it is applied less ductile and pliable. 

The tar of southern climates has both faults ; and it was 
formerly necessary that the marine arsenals should be sup- 
plied with that made in the north of Europe ; but now that 
tar is manufactured in furnaces, according to the proc^ess of 
M. Darracq, in such a manner as to condense all the vola- 
tile oil, and thereby render the tar more fat, unctuous, and 
suitable for all purposes, it is employed for naval purposes, 
equally with the best tar of the north. 

The resins are insoluble in water, but very soluble in 
alcohol : they liquefy at a low temperature, and burn easi- 

* A description of the processes employed for extracting resins and 
forming all the resinous preparations known in commerce, may be 
found in my Chimie appliquie aux Arts. Vol. II. page 425-445. 



VEGETABLE I'lBRE. 149 

iy, giving out much smoke during combustion. Amongst 
our mountains the peasants have no other method of light- 
ing their dark dwellings, than by burning the wood of 
resinous trees. 

The solubility of resin in alcohol occasions it to be used 
as a basis in the spirit-of-wine varnishes : the dissolvent 
evaporates as soon as the varnish is applied, and leaves a 
coating of resin, which preserves the body from the action 
of air or water, and at the same time gives to it a bril- 
liancy, smoothness, and a beautiful color which may be 
varied at pleasure. 

The smoke of resin condensed and collected in cham- 
bers hung with linen or paper, forms the lamp-black which 
is commonly employed in painting, stamping, printing, and 
the composition of varnish. According to the experiments 
of Messrs. Gay-Lussac and Thenard, 100 parts of common 
resin contain 

Carbon 75.944 

Oxygen 13.337 

Hydrogen ..... 10.719 



ARTICLE VII. 

Vegetable Fibre, 

Vegetable fibre is the frame-work of all the solid parts 
of plants : it may be separated from vegetable substances 
by the repeated action of water and alcohol, aided by 
heat ; by maceration for a length of time ; or by distilla- 
tion. By the first method the juices which are lodged in 
the intervals of the fibres are dissolved ; by the second, 
these juices are decomposed by fermentation ; by the third, 
which is the least perfect, those principles which can be 
volatilized by heat are driven off, but their carbon remains 
united to that of the fibre, which is itself decomposed, thouo-h 
preserving its form. 

Fibre separated from all other vegetable substances by 
either of the two first-mentioned processes, is possessed of 
a great degree of flexibility, is insoluble in water or alcohol, 
and burns with a yellow flame. 

Art has succeeded in extracting the vegetable fibre from 
13* 



150 CHYMISTRY APPLIED TO AGRICULTURE. 

a great variety of plants, by separating from it all those 
substances which would serve to hasten its putrefaction, 
or to diminish its flexibility : thus when the stalks of flax, 
hemp, broom, nettles, or the leaves of the aloe, are mace- 
rated in water, all the juices are extracted by dissolution 
and fermentation, and there remains only the flexible fibre, 
from which fabrics of linen, thread, and cordage, so exten- 
sively used, are manufactured. 

The opinion which some have entertained that those 
stalks, which had been bruised by machinery, did not re- 
quire to be softened by the action of water, appears to be 
erroneous : a portion of the juices may, it is true, be sepa- 
rated by mechanical force, but there remain some portions 
which adhere so closely to the fibre, that they can only be 
separated by maceration in water ; should these be allowed 
to remain, they would render the fibres unfit for many pur- 
poses, and would likewise be injurious to their strength. 

The size of the fibre is not the same in all the plants 
I have just mentioned ; that of flax is finer, and more deli- 
cate than the others ; from this the finest linens, cambrics, 
and lawns are made. The fibre of hemp is next in quality 
to that of flax, and is in general use : some coarse fabrics 
are made from the annual shoots of the broom ; and the fibre 
of the leaves of the aloe is manufactured into cordage. 

The fabrics manufactured from vegetable fibre, continue 
to grow soft and pliable by use, till the threads lose their 
consistency and tenacity ; when reduced to this state, they 
are by the action of machinery torn into fragments, and the 
cohesion between the particles destroyed by means of putre- 
fying liquids, and thus a fluid paste is formed, of which all 
the particles, having no union amongst themselves, swim 
separately in the water. These particles may, however, 
upon being taken from the water which divides and sepa- 
rates them, be made to adhere strongly to each other by a 
series of operations the execution of which constitutes the 
art of making paper. After having reduced the fibre to 
a pulpy liquid, the next step is to throw the liquid upon 
a sieve which allows the water to pass through, whilst a 
thin layer of the paste remains adhering to the net-work 
of the sieve : this takes some consistency by being sepa- 
rated from the water which held it in solution, and its 
firmness is further increased by drying : each layer forms 
a leaf, which only requires pressing and sizing, to be ready 
for use. 



VEGETABLE FlBUl. 151 

Though m the manufacture of paper, only fragments 
which have been thoroughly rotted are made use of, yet 
there will be found in the products the same kind of ine- 
quality as to fineness, as in the manufacture of cloths : the 
finest paper is made from linen rags, the coarsest from the 
remnants of ropes. 

Charcoal consists almost entirely of the constituent prin- 
ciples of vegetable fibre, from which the other elements 
have been separated by the action of heat ; and as charcoal 
forms the basis of vegetable fibre, I cannot well avoid speak- 
ing of it in connexion with this subject ; and as it is an 
article of such general use, it ought surely to find a place in 
a work of this kind. 

The vegetables of which the combustion is the most in- 
tense and lasting, are those which in their texture are 
closest and driest : such give out less flame in burning than 
others, but the heat is greater, and the superior quality of 
the coals produced from them causes them to be preferred 
for domestic heat, and for many of the operations of the arts. 

In some manufactures where it is necessary to apply heat 
to bodies which collectively form a large mass, as in the 
manufactories for porcelain and potter's ware, in lime-kilns, 
&/C., wood split fine and well dried is preferred, as it gives 
out much flame, and leaves but a small residuum of 
charcoal. 

Those plants in which the longitudinal fibres are disposed 
in closely compacted bundles, possess all the qualities 
necessary for combustion ; but the process is much less per- 
fect in those which have not acquired this density, and are 
still full of nutritive juices, than in those which have be- 
come by age hardened into wood. 

Soil, exposure, climate, and season modify in a remarka- 
ble manner the fibre of vegetables of the same kind. 

Vegetables raised in a dry and arid soil have a much hard- 
er and more compact texture, than those of the same kind 
raised in a moist and rich soil : they have more perfume, 
contain a greater quantity of volatile oil, are decomposed 
with more difficulty, and during combustion give out a 
much more intense heat. Every one knows that thickets 
having a southern exposure, yield better fuel than those 
which lie towards the north ; the wood is more solid, and 
after having been cut, it will resist for a longer time the 
action of air and water. This fact was observed by Pliny, 
in regard to the woods of the Apennines. 



152 CHYMISTRY APPLIED TO AGRICULTURli. 

The plants of southern climates, when transported to the 
north, lose their perfume; and the insipid vegetables of 
Greenland acquire taste and smell when transplanted to the 
gardens of the south of Europe. 

In the spring of the year, trees are full of juices, but 
they yield at that time principally mucilage ; in autumn 
they afford oil, starch, sugar, &lc. Professor Plot remarks, 
that in the year 1692, trees cut in the sap were devoured 
by worms, and that the wood warped in drying and ac» 
quired but little hardness. Julius Caesar was convinced of 
this truth when he caused his vessels to be built of wood 
cut in the spring. And Vitruvius advised that trees should 
be cut down only at the close of winter, " when the power 
of the cold shall have compressed and consolidated the 
wood." 

Vegetable fibre burns in the open air with a yellow 
flame, and disengages water and carbonic acid ; distilled 
in close vessels it leaves a residuum of carbon ; it is by 
this process, that the charcoal used for most purposes is 
procured. 

The most common method of procuring charcoal con- 
sists in cutting the branches and young trunks of trees into 
billets of about three feet in length, and two inches in 
diameter ; a portion of the prepared wood is laid upon the 
ground in parallel lines, and the remainder is piled upon it 
in a hemispherical form, to the height of six or eight feet ; 
the surface is then covered over with earth or sods of grass, 
and the pile set on fire by means of a flue in the centre. 
In a short time the whole mass is heated through, and 
water, carbonic acid, and volatile oil are thrown out with 
the smoke ; this will cease to appear when the wood is 
reduced to a black, sonorous body, and the pile may then 
be opened. 

This process is very faulty, as in it a great part of the 
wood intended to be carbonized is burned up, and because 
great skill is requisite for carbonizing the mass uniformly. 

Wood reduced to charcoal yields from -^^^ to -^jP^ of its 
weight, according to the nature of the wood, and the care 
with which the operation has been performed. 

Different kinds of wood yield coal of very different 
quality : the best coal is heavy and sonorous, and is pro- 
duced from wood of very compact fibre. The heat it af- 
fords is quick and strong, and its combustion, though vigor- 
ous, lasts a long time. The charcoal of the green oak of 



TEGETABLE FIBRE. 153 

the south burns at least twice as long as that of the white 
oak of the north, and the effects produced by the heat it 
affords are great in the same proportion. 

The light, porous white woods afford a brittle, spongy 
coal of less weight, and which may be easily reduced to 
powder : this coal consumes quickly in our fire-places, but 
is useful for some purposes, particularly in the manufac- 
ture of gun-powder, for which use it is prepared by the 
following process : a ditch of five or six feet square, and 
of about four in depth, is dug in a dry soil ; the ditch is 
heated by means of a fire made of split wood, the shoots 
and leaves are stripped from the young branches of elders, 
poplars, hazles, and willows, of which the coal is to be 
made, and as soon as the ditch is sufficiently heated the 
branches are thrown gradually in ; when carbonization is 
at its height, the pit is covered over with wet woollen 
cloths. This charcoal is more liffht and inflammable than 
that of the denser woods, and is susceptible of being more 
easily and completely pulverized. M. Proust, who has 
made numerous experiments to ascertain the kind of plants 
which furnish the best coal for powder, found that pro- 
cured from the stalks of hemp to be preferable to any 
other. 

The most perfect process of carbonization is performed 
by means of a close apparatus : for this purpose a stone or 
brick building is constructed, of from eighteen to twenty- 
five feet square ; this is vaulted over, and the inside of it 
lined with a brick wall ; through the extent of it cast-iron 
cylinders are laid in such a manner, that one of the two 
ends shall have an external communication, whilst the 
other carries the smoke into one of the chimneys. As soon 
as the building is filled with the wood for carbonization, the 
cylinders may be heated. The vapor which is distilled 
from the wood is received into sheet-iron pipes, placed in 
the top, which convey it into tubs where it is condensed. 

The form and dimensions of these buildings for making 
charcoal by means of a close apparatus, are greatly va- 
ried, but of all which I happened to see, the one I have 
here described appears to me the most perfect. There are 
many advantages arising from the use of this method, 
which more than repay the necessary expense of the appa- 
ratus. In the first place, a much greater quantity of char- 
coal is obtained, than by the ordinary process ; in the 
second place, well made and clean charcoal is always pro- 



154 CHYMISTRY APPLIED TO AGRICULTURE. 

cured ; and in the third place, there is obtained a great 
quantity of pyroligneous acid, which may be sold for 
$ 1.80 or $ 2.16 per French hogshead, and which, when 
purified and rendered clear, may supply the place of vinegar 
for many purposes. 

In addition to its very extensive usefulness in our work- 
shops and for domestic fires, charcoal possesses the prop- 
erty of destroying disagreeable smells, and of preventing 
or retarding putrefaction ; it is likewise useful in clarify- 
ing water, which, by being filtrated through it, loses the 
bad odor, which it in some instances possesses. When 
the inside of a cask is charred according to the plan of 
M. Berthollet, water may remain in it a long time unal- 
tered, and without acquiring any bad taste. I do not 
doubt that the same good effect would be produced upon 
wine, which often acquires from the cask so disagreeable 
a taste as not to be drinkable. 

An analysis of oak wood, and one of beech also, gave to 
Messrs. Gay-Lussac and Thenard the following results. 
100 parts of oak wood, 

Carbon 52.53 

Oxygen 41.78 

Hydrogen .... 5.69 
100 parts of beech wood, 

Carbon 51.45 

Oxygen 42.73 

Hydrogen .... 5.82 



ARTICLE VIII. 

Gluten and Albumen. 

Gluten and albumen are substances, which, although 
found in the vegetable kingdom, have all the properties of 
animal matter ; they yield an abundance of ammonia by 
distillation or putrefaction. 

Gluten and albumen, although possessing some common 
properties, cannot be considered as the same, as there is 
an essential difference between them. 

Albumen is an insipid fluid soluble in cold water, from 
which it may be precipitated by alcohol, the acids, or tan- 



GLUTEN AND ALBUMEN. 155 

nin ; but the most distinguishing characteristic which it 
possesses, is that of coagulating at a degree of heat indi- 
cated by from 45° to 50° of the centigrade thermometer, 
(equal to from 113° to 122° Fahr.) 

Proust, Clark, Fourcroy, and Vauquelin have each 
proved the existence of albumen in the juices and fruits of 
most plants. 

The white of eggs consists of nothing but pure albu- 
men : nearly all the different parts of animals contain dif- 
ferent portions of it ; it is, however, most abundant in the 
blood. 

Besides the property which albumen possesses of serv- 
ing as food, it is employed for many purposes in the arts, 
particularly for clarifying fluids ; when used for this, it is 
diluted with water, and then mixed with the liquid which 
is to be clarified ; the whole is then heated to 65° or 70° 
Fahr., and stirred carefully so as to distribute the albumen 
equally amongst all its particles ; by increasing the heat 
the albumen is made to coagulate, when it rises to the top 
of the vessel, carrying with it all the particles which render 
the liquid turbid or cloudy ; the thick foam which this pro- 
duces when cooled, may be taken off with a skimmer, and 
the liquid be afterwards filtrated to remove any remaining 
particles from it. 

The juice of the fruit of the Hibiscus Esculentus, (eat- 
able hibiscus, Okra,) contains so great a quantity of albu- 
men, that in St. Domingo it is employed in clarifying 
liquors ; in Martinique and in Guadaloupe they make use 
of the bark of the slippery elm for the same purpose. 

As albumen dries easily, and covers all bodies to which 
it is applied in thin layers, with a smooth and shining var- 
nish, it is used for giving lustre to paintings, wainscots, &c. 

The albumen of eggs mixed with quicklime finely pow- 
dered and spread upon strips of linen, makes an excellent 
lute, to be applied over the joints of vessels for distilling, 
where it is necessary to avoid any loss of gas or vapor. 
The white of eggs is preferred for such purposes, because 
the albumen of it is more free from mixture than that of 
any other substance. An analysis of the white of eggs 
afforded to Messrs. Gay-Lussac and Thenard the following 
results : 100 parts of the white of an egg contained 

Carbon 52.883 

Oxygen 23.872 

Hydrogen 7.540 

Azote 15.705 



156 CHYMISTRY APPLIED TO AGRICULTURE. 

Gluten appears to exist more extensively than albumen 
in the vegetable kingdom ; it may be extracted from 
acorns, chestnuts, horse-chestnuts, apples, quinces, wheat, 
barley, rye, peas, and beans; from the leaves of the cab- 
bage, cress, hemlock, borage, and saffron ; from the ber- 
ries of the elder, the juice of the grape, &.c. ; it is, how- 
ever, contained in the greatest quantity in the grain of 
wheat, and it is from this that it is usually procured. 

In order to extract gluten, the flour of wheat must be 
kneaded into a paste with water ; this paste must be after- 
wards worked by the hand under a stream of water from a 
spout, till the liquid flows off" clear ; the starch, sugar, and 
all the other principles contained in wheat, which are solu- 
ble in water, are thus carried off, and there remains in the 
hands only a soft, elastic, glutinous, ductile, semi-transpa- 
rent substance, adhering to the fingers after it has lost its 
moisture, and exhaling an animal odor ; this substance is 
called gluten or the vegeto-animal principle. 

Gluten is destitute of taste, turns brown in the air, and 
putrefies in the same manner as animal substances do ; it 
is insoluble in alcohol, and but slightly soluble in water. 
Combustion and distillation disengage from it the same 
products as those furnished by animal matter. 

Wheat is composed almost entirely of starch and gluten „ 
The results of the analyses made by Davy, of the wheat of 
different countries is as follows : 

100 parts of fall wheat of excellent quality gave of 
starch. ... 77 
gluten .... 19 

100 parts of spring wheat 

starch. ... 70 
gluten .... 24 

100 parts of Barbary wheat 

starch .... 74 
gluten . . , . 23 

100 parts of Sicily wheat 

starch .... 75 
gluten .... 21 

The wheat of southern countries contains more gluten 
than that of the northern countries ; and the hard-grained 
wheat more than the soft-grained wheat of the same coun- 
try. That wheat which contains the most gluten, ferments 



TANNIN. 157 

the most easily when made into dough ; it is for this rea- 
son that the Italian pastes are made of the flour of the 
hard wheat from the Crimea, instead of that from the 
wheat of the north. 

Amongst all the different kinds of bread corn, those 
from the flour of which the best bread is made, and of 
which the dough rises or ferments the most readily, are 
those which contain the most gluten : they may be ranked 
in the following order. 

1. Wheat, containing from -jiy^^ to -^^^ of its weight of 
gluten. 

2. Barley, from ^§^ to yf ^ 

3. Rye, from ^^^ to yig- 

4. Oats, from ^-^^ to yf^ 

When grain or flour has undergone any change by which 
the gluten is destroyed, the bread made from it is bad and 
unwholesome, and such grain or flour should only be em- 
ployed for making starch. 

Flour which contains but little gluten, or which has been 
deprived of it, if made into bread, turns sour by fermenta- 
tion ; the dough does not rise, and when baked is acid, 
heavy, and indigestible. 

There are some very nutritive vegetables in which the 
starch, instead of being combined with gluten, as it is in 
the bread corns, is united with mucilage ; this is the case 
in peas, beans, and potatoes. The flour of these will not 
alone make bread ; but it is frequently used in years of 
scarcity, mixed with that of wheat, to increase the quantity 
of bread. Dough made of flour thus mixed does not fer- 
ment so completely, as that made entirely from wheat 
flour ; the bread, however, is well tasted and wholesome, 
and preserves its freshness for even a longer time than the 
other. 



ARTICLE IX. 

Tannin. 

Tannin, or the astringent principle, is contained in 
a great variety of vegetables ; it is of a brown color, high- 
ly astringent, and dissolves readily both in water and alco- 
14 



15S CHYMISTRY APPLIED TO AGRICULTURE. 

bol. Its predominant characteristic is that of affording 
an insoluble precipitate when added to a solution of gela- 
tine. It combines with a solution of iron, and forms a 
black precipitate. It enters into the composition of writ- 
ing ink, and of the greater part of the black dyes for 
cloth. 

Tannin cannot be procured perfectly pure without a 
great deal of difficulty, and the operations require a de- 
gree of nicety which can only be acquired by a close ac- 
quaintance with chymical manipulation. For the greater 
part of the purposes to which it is applied it is not requi- 
site that it should be freed from all foreign substances. 
The great affinity which tannin has for gelatine causes 
it to combine with that principle whenever presented to it, 
till the substances containing the gelatine are completely 
exhausted of it : the various proportions of tannin con- 
tained in the different kinds of bark used in the manufac- 
ture of leather are determined from this circumstance. 

The most important purpose to which tannin is applied 
is that of converting skins into leather, and for this pur- 
pose the tannin contained in the bark of the oak is gener- 
ally preferred. In this process layers of ground bark are 
placed alternately with layers of skins in a pit, the layers 
of bark being slightly moistened in order that the tannin 
may act readily. As the tannin combines with the gela- 
tine of the skin, the latter changes its color to a reddish 
brown, and its opacity and consistency are at the same time 
increased, till by the progress of the operation the change 
is carried on through the whole substance of the skin, and 
it is thus brought to the firmness of leather. This new 
combination, which consists entirely of a union of tan- 
nin and gelatine, is compact and resists putrefaction ; it 
can be cut with a knife by quick strokes, and employed 
for numerous purposes. 

The best leather is that which, by being allowed to re- 
main in the pit a long time, is formed gradually : in this 
case the slowness with which the combination takes place 
renders it more close and complete, than when the tan- 
nin is dissolved in water aiid the skins plunged into it. 
By this last process the thickest skin may be tanned in a 
few days, but the quality of the leather will be very 
inferior. 

An astonishing improvement has been made in the art 
of tanning since M. Seguin discovered that it consisted 



VEGETABLE ACIDS. 159 

entirely in producing an union of the astringent princi- 
ple with the gelatine, which constitutes nearly the whole 
substance of skins : since this fact has been ascertained, 
tanners make use of the liquor of tan which has been 
once applied, but of which the strength is not exhausted, 
to moisten the bark in the pits, by which the operation is 
accelerated, without any injury to the product, and leath- 
er is thus formed in three or four months, as completely 
as it would be in eighteen by the use of the bark in a 
nearly dry powder. 

Dry skins generally increase about one third part of 
their weight by tanning. The different kinds of bark 
used in tanning bestow various shades of color upon the 
leather produced. 

Tannin has a strong affinity for coloring principles, so 
that in many cases it serves as a mordant in stamping ; 
it is not then surprising that leather should retain the col- 
ors it receives so strongly. 



ARTICLE X. 



The Vegetable Acids. 



I HAVE already observed, that when the proportions of 
oxygen combined with hydrogen are more than sufficient 
for the formation of water, the vegetable product will have 
an acid character. It can therefore be a matter of but 
little surprise, that we find acids so abundant in the vege- 
table kingdom. 

The quantity of acid contained in plants varies greatly 
during the several stages of vegetation, and according to 
the circumstances by which the developement of the in- 
dividual is influenced. Plants raised in the shade, or 
which grow in cloudy, cold, or rainy seasons, when the 
transpiration of carbonic acid by the leaves cannot be 
carried on for want of the action of the direct solar rays, 
by which alone it is produced, accumulate the acid in 
their vessels, and consequently all their products partake 
of the same general character. The greater part of fruits 
are sour before arriving at maturity; but this is owing to 
the fact, that the mucilage and sugar, which are afterwards 



160 CHYMISTUY APPLIED TO AGRICULTURE. 

found in them, are not yet sufficiently developed to correct 
the acid and disagreeable taste. 

The vegetable acids which are found most extensively 
diffused in vegetables are the oxalic, citric, tartaric, ben- 
zoic, gallic, acetic, malic, prussic, &.c. The analysis of 
vegetables presents a great number of acids, but as they 
are found only in particular kinds of plants, and their 
uses are either very limited, or altogether unknown, I do 
not think it necesary to make here an enumeration of 
them. 

Most acids are crystallizable, and some of them can be 
brought into a concrete state as soon as they are separated 
from the other principles with which they are combined in 
the plant. Vinegar, or the acetic acid, crystallizes when 
highly concentrated ; M. Molierat prepared crystals of it as 
transparent as ice. 

Oxalic acid crystallizes in the form of four-sided prisms : 
the acid of commerce presents this appearance. M. Deyeux 
has found it free in the hulls of the chick pea, and it has 
likewise been extracted from the expressed liquor of the 
plant: it exists in the stalks and leaves of sorrel, and in the 
juice of all the varieties of rhubarb. 

It may be produced by the action of nitric acid upon most 
vegetable substances, especially sugar. 

Oxalic acid is soluble in water and alcohol ; cold water 
dissolves one half of its own weight ; boiling water a 
weight equal to its own : and alcohol -^^-^ of its own 
weight. 

This acid possesses a strong affinity for the metallic ox- 
ides, especially those of iron ; it has also the characteristic 
property of depriving other acids of lime combined with 
them, and of forming with it an insoluble salt ; and it is 
upon these qualities that its use in the arts is principally 
founded. 

Oxalic acid thrown into water containing any calcareous 
salt, causes the liquor to become turbid, and forms from it a 
deposit which is found to be the oxalate of lime. If the 
oxalate of ammonia be made use of for the above purpose, 
the action will be more speedy than if the oxalic acid be 
used pure ; because decomposition is accelerated by the 
exchange of principles constituting the two salts. 

The power which oxalic acid possesses of dissolving 
readily the oxide of iron, renders it exceedingly useful in 
the manufacture of stamped goods, especially of cotton 



VEGETABLE ACIDS. 161 

cloths. In this process the whole fabric is covered with a 
mordant of iron, which is afterwards removed by means of 
this acid combined with gum, so that the color applied ad- 
heres firmly only to those parts where the mordant has not 
been destroyed : this process is conducted with far more ease 
than that which was formerly practised, of applying the 
mordant with the block, reserving those parts untouched 
which were not to receive a fixed color. 

The oxalic acid is better than any other for removing 
ink spots from cloth : it is only necessary for this purpose 
to put a little upon the spot, and to moisten it with a drop 
of water, after which a slight rubbing with the hand and 
a little rinsing in pure water removes every vestige of the 
etain. 

Messrs. Gay-Lussac and Thenard obtained, from an an- 
alysis of oxalic acid, carbon, oxygen, and hydrogen, in the 
following proportions. 

100 parts of oxalic acid, 

Carbon 26.566 

Oxygen 70.689 

Hydrogen .... 2.745* 

Tartaric acid may be extracted from the juice of the 
mulberry, grape, currant, 6lc. This acid is almost always 
found in vegetables combined with potassa, with which it 
forms a nearly insoluble salt : it is this union which occa- 
sions it to be so easily precipitated from the liquors in which 
it is contained, especially when they ferment. The coats of 
tartar which are found deposited upon the sides of casks 
are a combination of tartaric acid, potassa, and extractive 
matter. 

When tartar and the lees of wine are burned together, 
they leave alight, grayish, alkaline residuum, known in com- 
merce under the name of tartarated ashes ; this product has 
its particular use in the arts. 

The crystallized substance known in commerce, and 
extensively used, under the name of cream of tartar, is 
prepared by dissolving tartar in water containing pipe- 
clay ; this solution, after having been filtrated, is carefully 
evaporated till crystallization takes place ; a part of the 
extractive matter of the tartar is separated and falls to the 
bottom of the vessel, the rest remains in solution. The 
crystals thus obtained are composed of potassa with an 

I* By the best analysis no hydrogen is found in oxalic acids. — Tb.] 
14* 



162 CHYMISTRY APPLIED TO AGRICULTURE. 

excess of tartaric acid ; when exposed to the air upon cloths 
they acquire a brilliant whiteness. 

From this last combination tartaric acid may be extracted 
by the followhjg process, for which we are indebted to 
Scheele. Dissolve cream of tartar in boiling water, and 
saturate the solution with chalk ; a precipitate of lime com- 
bined with the acid will be thrown down ; this must be 
separated, and sulphuric acid poured upon it in the propor- 
tion of one third of the weight of cream of tartar employed ; 
to this mixture apply a gentle heat for ten or twelve hours ; 
the sulphuric acid will combine with the lime and form an 
insoluble precipitate, whilst the tartaric acid will be set free 
and swim above it ; the whole must then be diluted with 
cold water, and the liquor filtrated and evaporated to the 
consistency of a sirup, when the tartaric acid will be pre- 
cipitated in a concrete state. When evaporation is carried 
on slowly and the sirup allowed to remain at rest, the acid 
crystallizes in long octahedrons : if these crystals be purified 
by being repeatedly dissolved, and the solution filtrated and 
evaporated, they become very white, and present the form of 
tetrahedral prisms, terminated by pyramids of four elongated 
faces. 

Tartaric acid is composed of 

Carbon 24.050 

Oxygen 69.321 

Hydrogen 6.629 

One of the acids most extensively found in the vegeta- 
ble kingdom is the malic ; this differs essentially from 
the two of which I have just spoken, in remaining always 
in a liquid state, and forming with lime a salt soluble in 
water. 

Malic acid may be procured by saturating the juice of 
apples with potassa, and decomposing the salt thus formed 
by means of the acetate of lead : the precipitate thus pro- 
duced must be washed, after which sulphuric acid must be 
poured upon it till the liquor retains no sweetish taste : an 
insoluble sulphate of lead is formed, which may be separated 
from the malic acid by filtration. Scheele, by whom this 
acid was discovered, has made many experiments to ascertain 
its existence in vegetables. 

Malic acid is found most abundantly in apples, barberries, 
plums, and sour grapes; red fruits furnish less of it, but it is 
found in a greater or less quantity in nearly all the products 
of vegetation. 



VEGETABLE ACID^. 16(J 

This acid exists naturally in all wines, but it is more 
abundant in those of the north than in those of the south ; 
it predominates in them when made of unripe grapes, 
or if the must have been badly fermented. White grapes 
contain less malic acid than red ones, and I believe the 
superiority of the liquor obtained from the first ought to 
be referred to this difference. Brandy made from wine 
abounding in this acid, turns vegetable blues red, and is 
of a bad quality. Malic acid has not as yet been made use 
of in the arts. 

Citric acid is found in large quantities in oranges and 
lemons, particularly in the last ; the skins of wild, hairy 
plums, the red currant, cherries, strawberries, and rasp- 
berries likewise contain it ; in these it is found united with 
malic acid in nearly equal proportions. 

The process given us by Scheele for obtaining and 
crystallizing citric acid, is the one we still make use of; the 
acid is saturated with lime, and the insoluble salt thus formed 
is decomposed by sulphuric acid diluted with water ; the 
liquor is then evaporated and the acid obtained in a crystal- 
line form : by being repeatedly dissolved, filtrated, and 
evaporated, the crystals are produced in the form of rhom- 
boidal prisms, of which the inclined planes are terminated 
at each end by a summit of four trapezoidal faces. 

In Sicily and some other countries where lemons grow in 
profusion, it is customary to extract the juice of the fruit 
and saturate it with lime; this citrate is afterwards sent to 
the places where it is to be consumed, and there the opera- 
tion of extracting the acid is terminated. The great quan- 
tity of mucilage which the juice of the lemon contains, pre- 
vents it from being kept for a long time, or conveyed to any 
considerable distance, without undergoing changes that affect 
its nature. 

The process of pressing the lemons is begun in November, 
and ended in March : the quantity of juice extracted de- 
pends on the ripeness of the fruit. The liquor is put into 
barrels, and either sent off, or what is preferable, sold on the 
spot to individuals engaged in manufacturing it into the 
citrate of lime, in order to prevent the decomposition, which 
exports of this nature always undergo. 

About -^^ of carbonate of lime is required to saturate 
a given weight of lemon juice : the citrate is carefully 
washed, and after being dried is sent to its place of desti- 
nation. 



164 CHYMISTRY APPLIED TO AGRICULTURE. 

When nothing more than the extraction of the citric 
acid is required, the process is conducted in the following 
manner. Sulphuric acid diluted with six or seven times 
its weight of water is thrown upon the citrate, the mixture 
being stirred as the citrate is turned in ; when decomposi- 
tion has fully taken place, the citric acid swims above the 
insoluble sulphate of lime which has been formed ; the 
whole is filtrated and the deposit washed ; the water of the 
washing is added to the acid, and evaporation is carried 
on in pewter vessels : this operation may be commenced 
by boiling the liquor rapidly, but in proportion as this 
becomes thickened the action must be diminished ; when 
the acid has acquired the consistency of a sirup it is re- 
moved from the lire and left to crystallize. After the 
crystals have been removed from the mother loatcr, ten or 
twelve times its own weight of water is added to it, and it is 
then treated in the same manner as the lemon juice. 

In order to obtain the crystals of citric acid perfectly 
pure, it is necessary to repeat the processes of solution, 
filtration, and evaporation, several times. When these 
operations are skilfully performed, the juice of the lemon 
yields about ^ of its weight in citrate of lime, and j^ of 
citric acid in crystals. 

Citric acid is very soluble in water, and advantageously 
eupplies the place of lemon juice for domestic purposes, 
and in the arts, both by its being freed from mucilage, 
which renders the juice liable to undergo speedy changes, 
and from the diminution of its bulk by concentration. 

To give a flavor to food, citric acid is much more agreea- 
ble than vinegar, on account of the aromatic particles it 
contains ; dissolved in water it forms a very wholesome 
drink : about 30 grains of this acid dissolved in a pint of 
water and sweetened with sugar, composes an excellent 
lemonade. From its refreshing and antiputrescent proper- 
ties, it is invaluable during the hot months, and especially as 
an article for sea stores of vessels in warm latitudes. 

Citric acid has also its peculiar uses in the arts; like the 
oxalic acid, it is employed in forming reserves in printed 
goods, and in removing spots of ink or rust. 

When the coloring principle of the saffron (carthamus 
tinctorius) is dissolved by an alkali and precipitated by 
citric acid, it produces, upon silk, an orange, scarlet, or 
light-red color ; when thrown down in the same manner 
upon a white, oily surface, it constitutes the vegetable red 
or rouge. 



VEGETABLE ACIDS. 165 

The constituent principles of citric acid are found in 
the following proportions ; 

Carbon 33.811 

Hydrogen 6.330 

Oxygen 59.859 

Acetic acid exists ready formed in the sap of plants ; 
it is sufficiently distinguished from all the other vegetable 
acids by the peculiar property it possesses of forming 
easily soluble salts with the earths and alkalies. 

When a plant or any other vegetable product is distilled, 
not only the acetic acid which it contains is extracted 
from it, but a great quantity of acid is formed by that de- 
composition and disunion of the constituent principles, 
which is produced by heat. The smoke which escapes 
from our fire-places is only a confused mixture of water, 
acetic acid, oil, carbonic acid, and carbon. 

The acid produced by combustion and distillation has 
been known for a long time under the name of pyroligneous 
acid : it was not suspected to be the same as vinegar. 

A vast quantity of this acid may be procured with great 
ease by the new method of carbonizing wood in close 
vessels : the acid thus procured is however combined 
with oil, which gives it a dark brown color, and a disa- 
greeable empyreumatic odor; but by a particular process 
it may be freed from all foreign matter, and rendered 
perfectly pure : to effect this, the acid must be saturated 
with lime or an alkali ; after which the oil must be car- 
bonized by exposing the new salt impregnated with it, to 
a degree of heat sufficient to effect that change ; the salt 
is then to be decomposed by pouring upon it sulphuric 
acid ; or, the same result may be obtained by decompos- 
ing the acetate of lime by means of an alkaline sulphate : 
in this case an exchange of bases takes place, and the 
acetate treated with sulphuric acid furnishes a very pure 
acid.* 

* Wood is distilled in a great iron retort, the bottom of which is 
of cast iron, and the sides of thick sheet iron ; when it is filled with 
wood the lid of it is carefully luted on with clay. 

For distillation the wood must be very dry and the sticks prepared 
of equal thickness. Each retort will contain two "voles" ( = 106 
cubic feet) of wood. The opening or flue by which the smoke es- 
capes, is placed at a distance of some inches from the bottom of the 
boiler or retort. The acid is carried by copper pipes into a vessel, in 
which the water is constantly renewed : the acid and tar flow by a 
cock into a close vessel. The inflammable gas passes through copper 



166 CHYMI9TRY APPLIED TO AGRICULTURE. 

The acid procured in this manner has some very great 
advantages over that obtained by the acidification of fer- 
mented liquors ; this, being distilled, is consequently puri- 
fied from any foreign substance, and can be throw^n into 
the market in so concentrated a state, as to render it 
much more active than vinegar of wine, and capable of 
producing effects which it is difficult to obtain from that. 

Even to the present day, all the acetic acid employed 
either for domestic purposes, or in the numerous opera- 
tions carried on in the workshops of the various arts, has 
been provided by the degeneration or decomposition of 
fermented drinks, such as wine, beer, cider, perry, &/C. : 
all these liquors are more or less spirituous, and contain a 
portion of mucilage, which tends continually to produce in 
them the acetous fermentation. 

To prevent the acidification of wine, the liquor should 
be put up in good casks, well stopped, and placed in a cool 
place, of which the temperature does not sensibly vary ; 

tubes into the fire-place, to heat the cylinder and increase the carbo- 
nization. 

The process of carbonization lasts five hours ; the cooling is com- 
pleted in about seven. 

The acid thus produced is very impure, but serves for the prepara- 
tion of pyrolignites of iron : in order to purify it, it must bt put into an 
iron boiler, saturated while cold with chalk, and the tar, which will rise 
to the top, skimmed off; the liquor must then be poured into another 
boiler, heated to ebullition, and the saturation continued up to this 
point ; sulphate of soda is afterward added, when there is formed 
sulphate of lime, which is precipitated, and acetate of soda, which 
remains in solution. The liquor must then be drawn off and evapo- 
rated till pellicles are formed, when it is thrown into large tubs, where 
it acquires solidity by cooling. 

An igneous fusion of this mass has been produced by heating it 
in a cast-iron boiler, till the water was all evaporated, and afterwards 
continuing the fusion to ignition ; the liquor was then poured into 
moulds in which it solidified ; in this state it is black, and easily 
soluble in hot water : a solution of it well filtrated and evaporated 
yields crystals of acetate of soda, which retain almost nothing of the 
empyreumatic odor. When these crystals are dissolved in water, and 
the solution decomposed by sulphuric acid, crystals of sulphate of 
soda are obtained, and acetic acid, which only requires distillation to 
be perfectly pure ; the acid then marks from eight to ten degrees of 
the aerometer of Baum6, (::= specific gravity of 1.060 to 1.075.) To 
obtain the acid in a crystalline state, it is sufficient to combine it 
with lime, and to decompose by sulphuric acid this salt slightly cal- 
cined : the sulphate of lime takes nearly all the water which re- 
mains in the acetate. 

The mother water of the first operations, evaporated to dryness and 
mixed with tar, serves as a combustible ; the ashes passed through a 
reverberatory furnace and afterwards leached affords very fine sub- 
carbonate of Boda, 



VEGETABLE ACIDS. 167 

it should be clarified in order to free it from the mucilage, 
which would cause it to ferment ; and care must be taken 
so to place the casks, that the liquor will not be liable, bj 
being jolted, or shaken, to have the mucilage, which >has 
been precipitated, mixed again with it. 

When wine has been well fermented, and all its muci- 
lage decomposed or precipitated, it is no longer capable of 
turning sour. I have kept some of the red wine of the 
south in uncorked bottles, upon a terrace exposed to the 
heat of the sun during a whole summer, without its under- 
going any other change than that of completely losing its 
color ; the coloring principle being precipitated in the form 
of pellicles or membranes, which remained swimming in the 
liquor. Towards the end of August, I put into two of these 
bottles, containing equal quantities, the juice of two apples, 
and at the end of a month the liquor was converted into 
vinegar. 

The care which is necessary to preserve wine unchang- 
ed, indicates the course to be pursued for converting it into 
vinegar : all that is required to accomplish this, is to expose 
the liquor to the air at a temperature of between 70° and 80° 
Fahrenheit : when the liquor does not contain any fermenta- 
tive matter, a portion of yeast may be added to it; or it may 
be put into casks, which are impregnated with acetic acid or 
which contain sour lees. 

I shall not undertake to enumerate the various uses to 
which vinegar is applied upon our tables, or in our kitch- 
ens ; its employment in the arts is at least as extensive 
and as varied; aromatic plants are distilled with it for 
perfumes, and it is used for dissolving iron, copper, lead, 
and alumine, to form mordants in dyeing, and colors in 
stamping. 

Messrs. Gay-Lussac and Thenard found acetic acid to 
contain carbon, oxygen, and hydrogen in the following 
proportions ; 

Carbon 50.224 

Hydrogen 5.629 

Oxygen 44.147 

Prussic Acid. Bitter almonds, peach stones, and the 
leaves of the laurel, when distilled, afford an acid, which 
forms, with a solution of iron and a small quantity of alka- 
li, a greenish blue precipitate : this acid bears a strong 
resemblance to that which is extracted from some animal 
substances, and which, when combined with iron, forms 
Prussian blue. 



168 CHYMISTRY APPLIED TO AGRICULTURE. 

M. Gay-Lussac, who has made a series of experiments 
upon prussic acid, found it to consist of carbon, azote, 
and hydrogen, combined in the following proportions ; 

Carbon 44.39 

Azote 51.71 

Hydrogen 3.90 

The two first elements of this composition form a radi- 
cal, which our distinguished author calls cyanogen : the 
combination of this with hydrogen constitutes the prussic 
or hydrocyanic acid. There exists in this acid no trace 
of oxygen, nor is it the only instance of the kind, which 
modern chymistry affords us. 

Combined with iron, prussic acid forms the valuable 
substance known by the name of Prussian blue, the use 
of which is so important in coloring and painting. M. Ray- 
mond has discovered a method of fixing this color so 
successfully upon silk, that indigo has almost disappeared 
from the coloring establishments of Lyons : a son of 
M. Raymond has been equally successful in his use of it 
for woollen manufactures. 

The vegetable kingdom furnishes many other acids, as 
the benzoic, gallic, mucic, kinic, &c. ; but as they are 
less abundant, and their uses very limited, I do not think 
it necessary to give here any account of them. 



ARTICLE XL 

The Fixed Alkalies. 

Potash is found, in greater or less quantities, in all 
vegetables ; soda generally in plants growing near the 
sea, or in soils impregnated with marine salt. 

The most convenient mode of obtaining potash is by 
burning vegetable substances, leaching the ashes, and 
evaporating a solution of them to dryness : this first prod- 
uct is known under the name of salts, and is employed in 
the arts ; it is colored, but becomes white by being cal- 
cined in a reverberating furnace ; it is then known by the 
name of pearlash. 

As the use of the salts and of pearlash in the arts is very 
extensive, and as there are few localities where they may 



FIXED ALKALIES. 169 

not be advantageously made, I have been of opinion, that 
a farmer might easily unite the manufacture of them to his 
agricultural labors, and thus increase the income arising 
from his lands : I shall therefore enter into some details 
respecting it. 

All plants do not yield the same quantity of ashes, nor 
do equal weights of the ashes of different plants afford the 
same quantity of potash. Of the comparative value of cer- 
tain vegetables, we may judge from the following Tables, 
prepared from the experiments of Messrs. the Superin- 
tendents-general of the powder and salt-petre works, for 
the year 1779, and from those of Messrs. Kirwan, Pertuis, 
and Vauquelin. 

15 



170 



CHYMISTRY APPLIED TO AGRICULTUKEo 



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FIXED ALKALIES. 



171 



The salt obtained by these operations loses by calcina- 
tion, in order to convert it into pearlash, 25 or 30 per ceiit. 
of its weight. 

The results of the experiments made by Kirwan upon 
1000 lbs. of each of the vegetables assayed, are as follows. 



Name of the vegetable. 


Product in ashes. 


Product in alkali. 


Stalks of maize . . . 


88.00 


17.05 


Giant sun-flower . . . 


57,02 


20.00 


Branches of the vine . 


34.00 


5.05 


Box 


29.00 


2.26 


Willow 


28.00 


2.85 


Elm 


23.05 


3.09 


Oak 


13.05 


1.05 


Aspen 


12.02 


0.74 


Beech 


5.08 


1.27 


Fir 


3.04 


0.45 


Fern, in August . . . 


36.46 


4.25 


Wormwood 


97.44 


73.00 


Fumitory 


219.00 


79.00 



Table of Mean Results of the Experiments of Messrs. Kir- 
wan, Vauquelin, and JPertuis, upon 10,000 par^s of lach 
plant. 

Elm 39 of potash. 

Oak 15 

Beech 12 

Vine 55 

Poplar 7 

Thistle 53 

Fern 62 

Cow thistle 196 

Wormwood 730 

Vetches 275 

Beans 200 

Fumitory 790 

In selecting plants to burn for potash, it is advisable to 
choose those that contain the most of it ; grasses, leaves, 
the stalks of French beans, of peas, melons, gourds, cab- 
bages, artichokes, potatoes, maize, and garget, are very 
rich in this alkali. The plants are first dried, and then 
burned, and the ashes leached. 



172 CHYMISTRY APPLIED TO AGRICULTURE. 

The operation is very simple : a tub is filled with ashes, 
upon which water is thrown till it stands upon the top ; in 
the course of a few hours the water filtrates through the 
ashes, and flows off by a vent in the bottom of the tub : 
this ley should mark 10° or 12° of the aerometer of Baume. 
(Sp. gr. 1.075 to 1.091.) The first leaching does not ex- 
haust the ashes entirely of all their alkali, and fresh water 
is therefore passed through them till they contain nothing 
soluble : this weak ley is added to new ashes, till it ac- 
quires a suitable degree of strength. 

The leached ashes form an excellent manure for damp 
or clayey soils ; and it is used advantageously in the manu- 
facture of black glass. 

Ley is most readily formed by using hot water, but I 
have confined myself to pointing out the simplest means 
for accomplishing the purpose, and those that require the 
least apparatus. 

The ley is a solution of potash, which may be extracted 
from it by evaporation : this process may be commenced 
in a copper boiler, into which a very fine stream of the ley 
should flow to replace that which evaporates : when the 
liquor has acquired the consistency of honey, it should be 
put into iron boilers to complete the operation. As the sub- 
stance thickens, care must be taken to remove that por- 
tion of it which adheres to the sides, and to stir the whole 
carefully with iron spatulas. When the substance con- 
geals and becomes solid upon being exposed to the air, it 
is poured into casks and thrown into commerce under the 
name of salts. 

The whole process is simple, and may be conducted 
upon our farms without any difficulty. The farmer can 
appropriate to himself this branch of industry without in- 
terrupting the usual course of his labors : broom, heath, 
thistles, ferns, brambles, nettles, &-c. may be collected 
during the days when agricultural business cannot go on, 
and in the dead season, and in the winter they may be 
burned, and the ashes leached. 

I do not propose to any farmer to calcine the salts, to 
reduce them to real potash, because he would need for this 
purpose a reverberating furnace, and the process would be 
one at variance with his customary employments. The 
salts are already applied to numerous uses in the arts : 
if the manufacture of them should become a domestic one, 
there would verv soon be establishments formed for con- 



FIXED ALKALIES. 



173 



vcTting the salts into pearlash, and thus extending the em- 
ployment of it. 

The salts and pearlash contain all the soluble salts that 
are found in ashes. M. Vauquelin, who has analyzed the 
various kinds of potash of commerce, with reference to 
the difference in their qualities, has obtained the following 
results. 1112 parts of each kind were subjected to ex- 
periment. 



Potash. 


Real 
quantity 
of alkali. 


Sulphate 

of 
potassa. 


Muriate 

of 
potassa. 


Insolu- 
ble re- 
siduum. 


Carboniq 

acid and. 

water. . 


From Russia 


772 


65 


5 


56 


234 


From America 


857 


154 


20 


2 


129 


Pearlash 


754 


80 


4 


6 


308 - 


From Dantzick 


603 


152 


14 


79 


304 


From Vosges 


444 


148 


10 


34 


304 



The salts and pearlash are much used in the arts : they 
form the basis of the soft soaps, and enter into the compo- 
sition of white glass : they are used in washing and bleach- 
ing : they are greatly employed in coloring, metallic cast- 
ings, the manufacture of salt-petre and alum : in short, 
there are few manufacturing establishments, in which 
they are not consumed in greater or less quantities. 

Soda exists in nearly all plants which grow in a soil im- 
pregnated with marine salt; but all of these do not furnish 
it equally pure, nor in the same quantity. 

The barilla (the calsola vermiculata of Linnaeus) is cul- 
tivated in Spain for the purpose of extracting from it the 
Alicant soda, which is one of the kinds most esteemed in 
commerce ; in nearly all the other countries lying upon 
the sea or upon the salt lakes, the plants growing upon 
their coasts are burned, in order to obtain from them this 
substance. The different kinds of soda contain different 
quantities of alkali, according to the character of the plants 
from \vhich they are procured ; hence arises a great dif- 
ference in their names, prices, and uses. 

For the manufacture of soda, the marine plants arc 
gathered at the season when their vegetation has termi- 
15* 



174 CHYMISTRY APPLIED TO AGRICULTURE. 

nated, and they are left to dry : a pit four feet square and 
three feet deep is dug in the earth ; this is heated with 
split wood, and the saline plants are afterwards thrown 
gradually in : combustion is continued during seven or 
eight days ; the ashes become fused in the pit, and remain 
in this state till the end of the process: when the combus- 
tion is completed, the whole is allowed to cool, and then 
the block of soda is divided into large pieces for the market. 

I have always observed that when this mass of soda 
bubbles up in the pit, there escape from the surface jets 
of flame which appear to arise entirely from the combus- 
tion of sodium ; the perfect resemblance which the flame 
bears to that of the burning metal, struck me very forci- 
bly when I saw sodium burned for the first time. 

The plants which are most commonly burned for ob- 
taining soda, upon the borders of the Mediterranean and 
of the ocean, are the salicornia europea, the salsola tragus, 
the statice limoniurn, the triplex portulaco'ides, the salsola 
Jcali, the icareck, &lq,. The soda which is afforded by some 
of these is of a middling quality : the richest in alkali is 
the salicornia ; in some of them it does not exist sensibly; 
these abound in muriate and sulphate of soda mixed and 
strongly [frittes) fused with lime, silica, alumina, and 
magnesia ; the soda extracted from these plants, though 
weak, has nevertheless its use in the arts; it is employed 
in glass works, where, by means of the lime it contains, 
and the charcoal which is made to enter into the composi- 
tion for making glass, the sulphate of soda is decomposed, 
and the salt being left free promotes the fusion of the 
earthy substances. When soda contains 10 or 12 per cent, 
of alkali, it serves to make weak leys in the soap manufac- 
tories. 

In addition to the sod«a procured by the combustion of 
marine plants, chymistry furnishes us with the means of 
supplying it to commerce by the decomposition of the mu- 
riate of soda or marine salt ; this is converted into a sul- 
phate by means of sulphuric acid, and the last formed salt 
afterward decomposed in a reverberatory furnace, in which 
it is mixed with charcoal and chalk. 

The soda of commerce is never pure ; it contains at the 
utmost but 30 or 40 per cent, of alkali : a solution of 
it evaporated, yields octahedral crystals with rhomboi- 
dal bases ; these crystals consist of alkali and carbonic 
acid. 



FIXED ALKALIES. 175 

In order that soda may possess all the requisite strength, 
it is necessary to separate it from the carbonic acid with 
which it is always united, and by which its properties are 
weakened. This is easily done by mixing quick-lime with 
a solution of soda. The acid has so strong an affinity for 
lime as to quit the soda to combine with it. The ley pro- 
cured from this mixture is caustic, and leaves a burning 
impression upon the tongue : the soda thus purified acts 
more readily upon the bodies with which it combines. 
This mode of preparation is indispensable when soda is to 
be employed with oil in the manufactory of hard soap ; it 
is useless when it is to be combined at a strong heat with 
earthy bodies, as is the case in glass works. 

Davy discovered soda and potash to be metallic oxides, 
or burnt metals ; and Berzelius has proved that when 
these two alkalies are pure, potash is composed of -^^^ of 
oxygen, and -^j^-^ of potassium, and that soda was the result 
of 74.42 of sodium in 100 parts, and 25.58 of oxygen. 

Besides the substances of which I have spoken, plants 
contain certain salts, earths, and metallic oxides, which 
have never been extracted, either for domestic purposes or 
to be employed in manufactures : the existence of these 
is however so constant, their proportions so little varied in 
the same kind of plant, and their situations in the different 
parts of vegetables so marked, that they must be regarded 
as belonging essentially to vegetation, and not as being in- 
troduced accidentally and without design into the organs 
of the bodies in which they are found. 

The most abundant salts in plants are the sulphate of 
potash, and common salt, the phosphates of lime, and the 
nitrate of potash : the sulphate and muriate of soda do not 
exist in any considerable quantity, excepting in marine 
plants. 

Of the four earths procured from these plants by com- 
bustion, the one most extensively found is silica ; next to 
that comes lime, and afterwards magnesia and alumina. 

M. Th. de Saussure, in his highly valuable work upon 
vegetation, has given us the results of the analytical inves- 
tigations he has made for determining the quantity of 
ashes, salts, earths, and metallic oxides, which are fur- 
nished by an equal weight of a great variety of vegetables : 
these results are as follows. 



176 



CHYMISTRY APPLIED TO AGRICULTURE. 



Names of Plants. 



1. 

2. 
3. 

4. 
5. 

6. 
7. 



9. 

10. 
11. 
12. 

13. 
14. 

15. 

16. 

17. 

18. 
19. 
20. 

21. 
22. 

23. 
24. 
25. 
26. 

27. 

28. 
29. 



o Cu &. 

IB O Qj 

OJ r-i OJ 

to C fac 



Leaves of the oak, [quercus robivr^) of the 

10th of May 

The same of the 27th of September 

Stems or branches of young oaks stripped 

of their bark, 10th of May . 
Bark of the above-mentioned branches . 
Wood of the oak separated from the al- 
burnum ...... 

Alburnum of the wood above-mentioned . 

Bark of the trunks of the oaks above-men- 
tioned 

Liber of the above-mentioned bark . 

Extract of the wood of the above-mentioned 
oak ....... 

Mould of oak wood 

Extract of the above mould 

Leaves of the poplar, {jpopulus nigra,) of the 
26th of May 

Leaves of the same of the 12th of September 

Trunks of the same poplars stripped of their 
bark, September 12th .... 

Bark of the same trunks .... 

Leaves of the nut tree, [coryllus avellana,) 
of the 1st of May 

The same washed with cold distilled water 

Leaves of the nut tree of the 22d of June 

The same of tlie 20th of September 

Branches of the same tree stripped of their 
bark, 1st of May 

Bark of the same branches . . . | 

Wood of the Spanish mulberry tree, [morus 
nigra,) separated from the bark, November 

Alburnum of the same .... 

Bark of the above branches 

Liber of the bark ..... 

Wood of the yoke elm, [carpinus betulus,) 
separated from the alburnum 

Alburnum of the above .... 

Bark of the same 

Trunks, and branches stripped of their leaves, 
of the chestnut, [(BscvIus hippocaslanum,) 
10th of May ... . . 



13 
24 



23 
41 



28 
31 



4 
4 

88 





O 








w 


ci 






■t^ 


^ 




fl 


a 


fVi 


O 


o 


p., 


M 


c-> 


>1 


a-. 






J2 




T3 


72 


a 




< 








53 






55 





FIXED ALKALIES. 



177 



Water of vegeta- 
tion in 100 parts of 
the plants when 
green. 


a 

CO "^ 


s 

VI 

O 

a. 
>> 

«-> 


O 

11 
ci 
O 

w 


d 

o 

in 


03 

o 

<D 


Loss. 


745 


47 


24 


0.12 


3 


0.64 


25.24 


549 


17 


18.25 


23 


14.5 


1.75 


25.5 


u 


26 


28.5 


18.25 


0.12 


1 


32.58 


u 


7 


4.5 


63.25 


0.25 


1.75 


22.75 


u 


38.6 


4.5 


32 


2 


2.25 


20.65 


il 


32 


24 


11 


7.5 


2 


23.5 


il 


7 


3 


66 


1.5 


2 


21.5 


(( 


7 


3.75 


65 


0.5 


1 


22.75 


» 


51 


U 11 


U (I 


U 11 


(( u 


<( il 


li 


24 


10.5 


10 


32 


14 


8.5 


u 


66 


u u 


« u 


« u 


(( (( 


il u 


652 


36 


15 


29 


5 


1.25 


15.75 


565 


26 


7 


36 


11.5 


1.5 


18 


11 


26 


16.75 


27 


3.3 


1.5 


24.5 


u 


6 


5.3 


60 


4 


1.5 


23.2 


u 


26 


23.3 


22 


2.5 


1.5 


24.7 


u 


8.2 


19.5 


44.1 


4 


2 


22.5 


655 


22.7 


14 


29 


11.3 


1.5 


21.5 


557 


11 


12 


36 


22 


2 


17 


(( 


24.5 


35 


8 


0.25 


0.12 


32.2 


u 


12.5 


5.5 


54 


0.25 


1.75 


26 


u 


21 


5.25 


56 


0.12 


0.25 


20.38 


u 


26 


27.25 


24 


1 


0.25 


21.5 


il 


7 


8.5 


45 


15.25 


1.12 


23.13 


ii 


10 


16.5 


48 


0.12 


1 


24.38 


346 


22 


23 


26 


0.12 


2.25 


26.63 


390 


]8 


36 


15 


1 


1 


29 


346 


4.5 


4.5 


59 


1.5 


0.12 


30.88 


u 


9,5 


u u 


li (( 


U (( 


(( il 


(( H 



178 



CHYMISTRY APPLIED TO AGRICULTURE. 



Names of Plants. 



30. 
31. 
32. 
33. 
34. 
35. 
36. 
37. 

38. 
39. 
40. 
41. 
42. 



43. 

44. 
45. 

46. 



47. 

48. 

49. 
50. 
51. 
52. 
53. 

54. 

55. 
56. 
57. 

58. 



Leaves of the chestnut, 10th of May 

Thesarr.2 ofthe 23d of July . 

The same of the 27th of September 

Flowers of the same .... 

Ripe fruits of the same, 5th of October . 

Pea vmes, {pisum sativum,) in flower 

The same bearing ripe seeds . 

Plants of the marsh bean, [vicia fabia,) be- 
fore flowering, 23d of May . 

The same whilst in flower, 23d of June 

The same bearing their ripe seeds . 

The same separate from their ripe seeds 

Seeds of the same 

Bean plants in blossom, raised from seeds of 
the same kind, and watered with distilled 
water 

Golden rod, {solidago vulgaris,) before flow 
ering 

The same when ready to flower, 15th of July 

The same bearing ripe seeds, 20th of Sep 
tember 

Plants of the turnsol, [helianthus annuus,) of 
the 23d of June, one month before flow 
ering 

The same when beginning to flower, 23d of 
July 

The same of the 20th of September, bearing 
their ripe seeds .... 

Plants of wheat, {triticum sativum,) in flower 

The same bearing ripe seeds . 

The same one month before flowering . 

The same when it flowers, 14th of June 

The same of the 28th of July, bearing ripe 
seed ... ... 

Straw of the above wheat separated from the 
seed 

Kernels selected from the above wheat . 

Wheat bran 

Plants of maize, [zea mats,) of the 23d of June, 
one month before flowering . 

The same of July 23d, in flower 



PS O w 

o cf^ 

" fl be 



16 
29 
31 
9 
12 



16 

20 

(( 

u 



13 
23 



16 




FIXED ALKALIES. 



179 



Water of vegeta- 
tion in 100 parts of 
the plants when 
green. 


a; 


Earthy phosphates. 


a 
o 

u 

H 




V 

% 


o 


782 


50 


U (( 


u u 


u u 


a u 


u u 


652 


24 


U (( 


« u 


<( u 


u u 


a u 


636 


13.5 


(( « 


(( u 


(( u 


» « 


u u 


873 


50 


(( (( 


u u 


(( « 


(( (( 


il u 


647 


75 


10.5 


a u 


0.75 


0.5 


13.25 


(( 


49.8 


17.25 


6 


2.3 


1 


24.65 


u 


34.25 


22 


14 


11 


2.5 


17.25 


895 


55.5 


14.5 


3.5 


1.5 


0.5 


24.50 


876 


55.5 


13.5 


4.12 


1.5 


0.5 


24.38 


(( 


50 


17.75 


4 


1.75 


0.5 


26 


(( 


42 


5.75 


36 


1.75 


1 


12.9 


(( 


69.28 


27.92 


u u 


(( u 


0.5 


,2.3 


(( 


60.1 


30 


u u 


U (( 


0.5 


9.4 


(( 


67.5 


10.75 


1.5 


1.5 


0.75 


18.25 


tt 


59 


8.5 


9.25 


J. 5 


0.75 


21 


u 


48 


n 


17.25 


3.5 


1.5 


18.75 


u 


63 


6.7 


11.56 


1.5 


0.12 


16.67 


877 


61 


6 


12.5 


1.5 


0.12 


18.78 


753 


51.5 


22.5 


4 


3.75 


0.5 


17.75 


(( 


43.25 


12.75 


0.25 


32 


0.5 


12.25 


(( 


11 


15 


0.25 


54 


1 


18.75 


(( 


60 


11.5 


0.25 


12.5 


0.25 


15.5 


699 


41 


10.75 


0.25 


26 


0.5 


21.5 




10 


11.75 


0.25 


51 


0.75 


23 


22.5 


6.2 


1 


61.5 


1 


78 


(( 


47.16 


44.5 


u « 


0.5 


0.25 


7.6 


(( 


4.16 


46.5 


(( (( 


0.5 


0.25 


8.6 


u 


69 


5.75 


0.25 


7.5 


0.25 


17 


u 


69 


6 


0.25 


7.5 


0.25 


17 



180 



CHYMISTRY APPLIED TO AGRICULTURE. 



3 



Names of Plants. 



59. Plants of maize bearing ripe grain . 

60. Stalks of the same separated from their ripe 
ears ....... 

61. Ears of the above stalks .... 

62. Kernels of the above maize . 

63. Straw of barley, [hordeum vulgare,) separated 
from its ripe seeds .... 

64. Grains of barley from the above straw 

65. Grain of barley 

66. Oats 

67. Leaves of the rose-bay, [rhododendrum ferru- 
gineum,) growing upon Jura, a calcareous 
mountain, June 20th .... 

68. The same growing upon Breven, a granitic 
mountain, 27th of June 

69. Stalks and branches of the rose-bay growing 
upon Jura, 20th of June . . . 

70. Stems of the rose-bay from Breven, 27th of 
June 

71. Leaves of the pine, {pinus ahies,) growing 
upon Jura, June 20th .... 

72. The same growing upon Breven, June 27th 

73. Branches of the pine stripped of leaves, June 
20th 

74. A variety of whortleberry, [vaccinium myr- 

tillus,) growing upon Jura, August 29th 

75. The same growing upon Breven, August 20th 



m 



42 fl 

a 



<u 



b£ 



S „ a3 

o ^ 

M O f*> 



46 

84 
16 
10 

42 

18 

u 

31 



30 
25 

8 

8 

29 
29 

15 

26 
22 



FIXED ALKALIES. 



181 



^ 23 ^ . 

t(-i O ♦^ 41 

o o c <u 

s s ^ 

o -^ 



^•2' 



02 



72.45 

62 

20 

29 

22 

1 



23 

21.1 

22.5 

24 

16 
15 

15 

17 
24 



CIS 

&. 
O 



5 

(( it 

36 

7,75 
32.5 
22 
24 



14 

16.75 

10 

11.5 

12.27 
12 



18 
22 



a 
o 

It 

ei 

ll 

H 



1 

u il 

12.5 

u u 



43.25 
16.75 
39 
29 

43.5 

29 



42 
22 



92 



18 



57 

35.5 

21 

60 



0.75 

2 

05 

1 

2.5 
19 



1.5 
5 



0.5 

u u 

0.12 

0.5 
0,25 
0.12 
0.25 



3.25 

5.77 

5.4 

11 

1.6 
5.5 



3.12 
9.5 



o 



3.5 

u u 

0.88 

2.25 

2.8 
29.88 
14.75 



15.63 

31.52 

22,48 

24.5 

24.13 
19.5 



19.38 
17.5 



16 



182 CHYMISTRY APPLIED TO AGRICULTURE- 



CHAPTER X. 

ON THE PRESERVATION OF ANIMAL AND VEGETABLE 
SUBSTANCES. 

Each product of agriculture has its season ; there are 
few which the earth yields at all times. From' this well- 
known truth there result two incontestable facts ; the first 
of these is, that in the years of abundance the production 
is greater than the consumption, and consequently a part 
is lost, and the remainder sold at a low price ; the second is, 
that the consumption of the greater part of the articles of 
agricultural produce takes place within one year, whilst, if 
the agriculturist had sure means of preserving them, it 
might be prolonged indefinitely, and thus the sale of them 
rendered more profitable. The question of the best man- 
ner in which the productions of the earth may be pre- 
served, is then one of the most important to be solved in 
rural economy. 

Before making known the processes by which, as we 
have learned from experience, agricultural products may be 
preserved free from change, it is necessary to cast a glance 
upon the causes by which that change is produced. 

The natures of all bodies which have ceased to live or 
vegetate are changed, as soon as the physical or chymical 
laws by which they were governed, cease to act ; the ele- 
ments of which they were composed then form new com- 
binations, and consequently new substances. 

Whilst an animal lives, or a plant vegetates, the laws of 
chymical affinity are continually modified in its organs by 
the laws of vitality ; but when the animal or plant ceases 
to live, it becomes entirely subject to the laws of chymical 
affinity, by which alone its decomposition is effected. 

The principles of the atmospheric air which is imbibed 
by the organs of living bodies, whether animal or vegeta- 
ble, are decomposed and assimilated by them, whilst dead 
bodies are decomposed by its action. Heat is the most 
powerful stimulant of the vital functions, yet it becomes 
after death one of the most active agents in the work of 
destruction. Our efforts, then, for the preservation of 
bodies ought to be directed to counteracting or governing 
those chymical or physical agents, from the action of which 
they suffer ; and we shall see that all the methods which 



PRESERVATION OF FRUITS BY DRYING. 133 

have been successful, are those which have been formed 
upon this principle. 

The ch3^mical agents, which exert the most powerful in- 
fluence over the products of the earth, are air, water, and 
heat ; the action of these, however, is not equally powerful 
over all classes of plants; the soft and watery, and those 
which approach the nearest to animal matter, decom_pose 
most readily ; the principles of such are less coherent, le^s 
strongly united than of others ; so that the action of disor- 
ganizing agents upon them is prompt and effectual. 

All the methods now employed for the preservation of 
bodies, consist in so far chano-ino; their nature, as to de- 
prive them of the elements of destruction contained with- 
in their own organs ; or in secluding the substances to be 
preserved from contact with the destructive agents men- 
tioned in the preceding paragraph ; or in causing them to 
imbibe certain other substances, the anti-putrescent quali- 
ties of which counteract all action, whether of internal 
or external agents. 



ARTICLE I. 



On the Preservation of the Fruits of the Earth hy 

Drying. 

In all vegetable products, water exists in two different 
states, one part of it being found free, and the other in a 
state of true combination : the first portion, not being 
confined except by the covering of the vegetable, evapor- 
ates at the temperature of the atmosphere ; the second is 
set free only at a temperature sufficiently high to decom- 
pose the substances containing it : the first, though for- 
eign to the composition of the vegetable, enters into every 
part of it, dissolving some of its principles, serving as a 
vehicle for air and heat, and being converted by cold into 
ice ; by these several properties it greatly facilitates de- 
composition : the second portion, from which no evil of 
the kind arises, is found combined and solidified in the 
plants, and its action is thus neutralized. Drying, then, 
consists in depriving the product to be preserved of the 
water contained in it in a free state, by heat; and from 



184 CHYMISTRY APPLIED TO AGRICULTURE. 

what has been observed above, it follows, that too great a 
degree of heat must not be applied, as, in consequence, 
the taste and the organization of the substance would be 
changed by a commencement of the decomposition of its 
constituent principles : the temperature should never be 
higher than from 35° to 45° of the centigrade. (= from 
95^ to 113° Fahrenheit.) 

Drying can be performed either by the heat of the sun 
or in stove rooms. In the southern climates the heat of 
the sun is sufficiently powerful to dry the greater part of 
the fruits, and thus to preserve them unaltered : the dry- 
ing is effected by exposing them to the rays of the sun 
upon hurdles or slates, where they will be protected from 
rain, dust, and injury from animals. Practice alone is 
sufficient to enable one to judge of the degree, to which 
each kind of fruit must be dried in order to its preser- 
vation. 

When the outer skin or rind of the fruit is of a kind to 
prevent the water from passing off freely, incisions are 
made in the rind to facilitate its evaporation. In this 
manner are prepared most of the dried fruits, which form 
60 considerable an article of commerce between the south 
and north. 

Those fi aits which contain much sugar, as pnines, figs, 
musk grapes, &lc., may be prepared in the above manner, 
and preserve nearly all their qualities, but the acid fruits 
acquire a disagreeable sharp taste by the concentration of 
the juices ; some of them, however, may be kept advanta- 
geously in this way. 

In the hottest countries the process of drying is often 
commenced by subjecting the fruits to the heat of an oven, 
after which they are exposed to the sun ; some kinds of 
fruits are thrown into a weak ley, till their surface becomes 
wrinkled, when they are taken out, carefully washed in cold 
water, and afterwards dried in the sun : cherries particular- 
ly are treated in this manner. When the heat of the sun is 
not sufficiently great to evaporate all the water contained in 
the pulp of large, fleshy fruits, they may be cut in pieces 
and then dried ; in this manner apples and pears are pre- 
pared for keeping.* 

But this method is neither speedy nor economical enough 

[ * In tliis country, apples, pumpkins, squashes, and peaches are 
kept by drying. — Tr.] 



PRESERVATION OF FRUITS BY DRYING. 185 

for such preparations as have but little value in commerce, 
and which can never supply, for domestic purposes, the 
place of those whole fruits, which may be easily preserved 
from one season to another : it is therefore customary to 
perform the drying either in stove rooms or ovens. In the 
first case, the fruits, after being cut, are placed upon hur- 
dles arranged in rows in a chamber heated to 112° : in 
the second, the fruits are put into an oven, from which 
bread has just been drawn ; this is repeated if the fruits 
be not sufficiently dried the first time. 

Some of the fruits referred to above, may be dried 
without being cut : of this kind are the tender pears, 
which cannot be preserved fresh through the winter ; such 
as the rousselet, the butter pear, the doyenne, the me»- 
sire-jean, the martinsec, &c. These are first peeled, and 
then thrown into boiling water, after which they are put 
upon hurdles into an oven heated less than is required for 
bread ; after an interval of three or four days the pears 
are again exposed to the same degree of heat, having been, 
however, first flattened between the palms of the hands; 
whence they have acquired the name oi pressed pears. 

Fruits prepared in either of the above ways are suscep- 
tible of fermentation upon being soaked in water, and 
they thus serve to make a cheap and useful drink. 

In those countries where these fruits abound, the dry- 
inor of them is commenced about the 1st of August, and 
those are made use of, which then fall from the trees ; in 
autumn, when the harvest is gathered in, the soundest 
and finest fruits are carefully selected to be used fresh, 
whilst the rest are dried and preserved in a place free 
from moisture, to be employed in making drinks. I shall 
in another chapter speak of the processes by which this is 
effected. 

The herbage, which serves as food for domestic animals, 
can be preserved only by drying, and this in all countries 
is practised at the time of cutting. Fodder, which is im- 
prudently stacked up whilst still damp, ferments, and the 
heat thus produced is sufficient to change the quality, pro- 
duce mouldiness, and is sometimes even great enough to 
set the whole on fire. 

There are some fruits, which may, by a few slight pre- 
cautions, be preserved throughout the year. The first of 
these precautions is, that of depriving their surface of 
all moisture before putting them up ; and the second con- 
16* 



186 CHYMISTRY APPLIED TO AGRICULTURE. 

sists in keeping them in dry places, where the temperature 
will constantly be between 50° and 54° Fahrenheit ; the 
third, in separating the fruits, so that they shall not come 
in contact; I have seen apples preserved in this manner 
eighteen months. It is necessary to be particular in select- 
ing fruit for preservation ; that only should be taken which 
is perfectly sound. 

Wood and other portions of vegetables, and various ani- 
mal substances, are likewise preserved by drying ; this pro- 
cess increases their hardness and renders them less accessi- 
ble to the action of air, insects, and other destructive agents. 

The process of drying is not confined to preserving 
fruits from decomposition : it furnishes the means of secur- 
ing their juices unaltered for the formation of extracts of 
them. 

When the juices of plants can be extracted by pressure 
alone, it is only necessary to evaporate these juices at a due 
degree of heat and in suitable vessels, till, being deprived 
of all the water which retained them in a liquid state, they 
are reduced to dryness. Evaporation, if continued for a 
long time at the temperature of boiling water, changes these 
juices a little ; the albumen, which is contained more or 
less abundantly in all sweet fruits, is coagulated, and after 
this they are no longer susceptible of undergoing the vinous 
fermentation. 

The must of grapes, operated upon in this manner, fur- 
nishes an extract called raisine, which is an article of 
food both wholesome and agreeable, and which, when 
soaked in water, decays without producing alcohol. The 
fermentative power of this substance may, however, be re- 
stored by mixing with it a little of the yeast of beer, as 
this repairs the loss, which the juices had sustained by 
heat during evaporation. 

All the juices obtained from sweet fruits may be convert- 
ed into extracts, and thus furnish agreeable food : the qual- 
ity of the extract varies according to the quantity of sugar 
contained in the fruit, and the care taken in the operation : 
when the juices are several times clarified, and evaporation 
carried on in a water bath, care being taken to stir the 
liquid to prevent its adhering to the sides, the color and taste 
of the extract or jelly obtained is far superior to that pro- 
cured without employing these precautions. 

The sweetest fruits, however, even the well ripened 
grapes of the south, contain a portion of acid, which. 



f 
PRESERVATION OF FRUITS BY DRYING. 187 

when concentrated by evaporation, acts upon the copper 
boilers in which the operation is carried on, so as to form 
an acetate of copper : this, by producing colics, would 
render the use of the extract dangerous, especially at the 
south, where the principal article of food for children is 
the ralsine. In order to obviate this serious evil, an an- 
cient and generally followed custom is observed : as soon 
as the must of the grapes begins to boil in the coppers, a 
bunch of keys is thrown in, and allowed to remain till the 
operation is completed : these keys attract the copper and 
become covered with the precipitate thus formed, and 
nothinor remains in the extract but the acetate of iron, 
which is not injurious. 

I have observed that the juices of all succulent fruits 
might be converted into extracts, and thus preserved for 
use in the course of the year; but the greater part of 
these juices, when concentrated by evaporation, are so 
excessively acid as to be totally unfit for food, and they 
only form, when mixed with water, a very sour drink. In 
order to correct or conceal this acidity, these juices are 
boiled with an equal weight of sugar, and thus made into 
sirups and jellies. 

As it is of importance to be able to extract and preserve 
for domestic purposes, for pharmacy, and for the arts, cer- 
tain vegetable products, which can be only very imper- 
fectly obtained by mechanical pressure, recourse is had to 
other means; those liquids are made use of which will 
dissolve the wished for principles, and the solution is 
afterwards evaporated to dryness. 

The fluid most generally employed for solutions is wa- 
ter ; this dissolves the extractive matter, mucilage, sugar, 
and the greater part of the salts, and mixes with the 
mealy portions of plants ; it may be applied cold or hot to 
the vegetables, or they may be boiled in it, accordhig 
to the nature of the principle to be extracted ; water will 
dissolve all that is soluble in them, and the extracts may be 
obtained from the solution by evaporation. 

The resins, which are found so abundantly in some 
vegetables, are not soluble in water, and the place of this 
liquid must be supplied by alcohol, in which the plant must 
be digested ; evaporation will separate the alcohol from the 
resin which it holds in solution. In order to avoid the ac- 
cidents that might occur from the dispersion in the at- 
mosphere of a very inflammable vapor, the evaporation 



18S CHYMISTRY APPLIED TO AGRICULTURE. 

must be so conducted that the dissolvent may be received 
into an alembic or close vessel. 

In addition to the methods of preserving fruits by drying, 
and by reducing their juices to the state of sirups and jellies 
by natural or artificial heat, M. de Montgolfin has applied 
the action of the air pump with great success. I have tast- 
ed juices prepared and thickened in this manner, and I 
thought they were much superior to those that had been 
evaporated in either of the modes hitherto usually practised. 
I do not doubt that, when this method becomes better known, 
it will be generally adopted. 



ARTICLE II. 

On the Preservation of the Fruits of the Earth by Sc' 
eluding them from the Action of Air, Water, and Heat. 

The atmospheric air coming in contact with fruits de- 
prives them of their carbon, and forms carbonic acid. 

Fruits exposed to the solvent action of water suffer decom- 
position by having the affinity existing between their con- 
stituent principles weakened, and at length destroyed. 

Heat dilates the particles of bodies, and thus diminishes 
the forces of cohesion and attraction, and favors the admis- 
sion of air and water. 

The combined action of these three agents produces 
very speedy decomposition ; the effect produced by any 
one of them is slower, and the results different. So that 
in order to preserve fruits from decomposition it is neces- 
sary to guard them from the power of these three de- 
stroyers. 

In several European countries, particularly in the north, 
roots of all kinds are preserved merely by secluding them 
entirely from air, heat and water ; this is done by digging 
deep ditches in a dry soil upon a spot a little elevated, and 
depositing in them the roots, which are afterwards cov- 
ered over with a layer of earth, of sufficient thickness to 
prevent them from suffering by the frost; over the whole 
is then laid a bed of straw, broom, or fern, in order to pro- 
tect them from rain and from the water of melting snows 
which might filtrate through into the pit. 



PRESERVATION OP FRUITS BY SECLUSION. 189 

Roots, to keep well, must have their surfaces entirely free 
from moisture before beinor thus buried. 

The roots have in themselves a preserving principle, which 
does not exist in a dead plant or one that has terminated 
its period of vegetation : they have as yet lived but a por- 
tion of their vegetable life ; they have not formed the seeds, 
which secure the continuance of their species; and to fulfil 
this great design of nature they profit by every circumstance, 
which can favor and confirm their vegretation ; but when 
placed for a time beyond the action of air, water, and heat, 
their organs remain at rest till again excited by the presence 
of these powerful agents. 

As dead bodies do not retain this animating principle, 
the energies of which are only suspended in roots, grains, 
&:.c. during the winter, so they suffer decomposition, 
though less rapidly, from the contact of air, heat, and 
water. 

In the way of which I have just spoken, beets, carrots, 
potatoes, and many other vegetables may be preserved unin- 
jured till summer. 

A very simple method of preserving them at least free 
from decomposition, is, to heap them up in piles upon a very 
dry soil, and then to cover them upon all sides with stravy 
enough to protect them from rain and frost : in England this 
is esteemed the best method of keeping turnips. 

Vegetables may likewise be preserved by heaping them 
up in barns to the height of five or six feet, care being taken 
to cover them well with straw or hay at the commencement 
of the severe cold weather. Should the roots in these heaps 
begin to vegetate, they must be removed, and thus their 
farther developement checked. 

Thomas Dallas has published some very important ob- 
servations * upon the modes of treating potatoes which have 
been affected by the frost. With us such potatoes are re- 
jected, as being unfit either for food or for furnishing 
fecula. The able agriculturist above mentioned considers 
them in three different states; 1st, when they are slightly 
touched by the frost ; 2d, when the outer portion of their 
substance is frozen ; and 3d, when they are frozen through- 
out. 

In the first case he finds that nothing more is necessary, 
than to sprinkle the roots with lime to absorb the water form- 

* jBibliotheque Universelle, Art. Agriculture. Vol. II. p. 123, 



190 CHYMISTRY APPLIED TO AGRICULTURE. 

ed under the skin, which would speedily occasion their com" 
plete decomposition. In the second instance he causes the 
potatoes to be pared and thrown for some hours into water 
slightly salted. When the potatoes are completely frozen, 
he finds them to yield, upon distillation, a spirituous liquor 
resembling the best rum, and affording much more alcohol, 
and that of a better quality, than can be procured from the 
roots before freezing. 

The preservation of grains has always been an object 
of much consideration both to governments and agricultur- 
ists, and it is a peculiarly interesting one, because bread 
forms so large a portion of the nourishment of Europeans, 
and because the scarcity and high price of it have been 
the cause or the pretext for popular discontents and insur- 
rections. 

The art of preserving grains unchanged, besides obviating 
this evil, presents the additional advantage to the agricultur- 
ist of enabling him to make a good harvest compensate for 
a bad one, by maintaining the price of bread stuff at a rate 
suitable alike for the consumer and the producer ; and thus 
avoiding those periodical successions of high and low prices, 
of abundance or scarcity, which disturb social order, and 
give rise to excesses prejudicial to all. 

It appears that the people of the most ancient times pre- 
served their grains uninjured through several years, mere- 
ly by secluding them entirely from the action of air and 
moisture. 

The Chinese have from time immemorial preserved their 
grains in pits, which they call teon : these ditches are 
either hewn out in rocks free from chinks and humidity, 
or what is still better, they are dug in a firm, dry soil. If 
there be any danger of humidity about the pits, they are 
lined with straw, or wood is burned in them to harden and 
dry the earth. The grain is not put into the pits till some 
months after the harvest, nor till it has been well dried in 
the sun ; it is then covered over with mats made of the 
chaff of the grain or of straw, and this again by a bed of 
earth well beaten down, that it may not be penetrated by 
water. 

Varro, Columella, and Pliny inform us, that the an- 
cients preserved their grain in ditches hollowed out of 
rocks or dug in the earth, the sides of them being lined 
with straw. Quintus Curtius relates, that the army of 
Alexander experienced great privation upon the banks of 



PRESERVATION OP FRUITS BY SECLUSION. 191 

the Oxus, because the inhabitants of the country preserved 
their corn in subterranean pits, the situation of which was 
known only to those who dug them.* 

I have several times had occasion to visit in Amboise 
what are called Cresar's granaries, and from examining 
the place, I think there can be no doubt that it was intend- 
ed for the preservation of grain. About thirty feet above 
the level of the waters of the Loire, there are dug in a dry 
and solid calcareous rock, deep and broad excavations ar- 
ranged in three stages separated from each other by vaults. 
Behind the first excavations, there are formed others, and 
separated from them by a wall of rock six or seven feet 
thick, and within these are built, of brick and mortar, cir- 
cular granaries of about fifteen feet in diameter : the up- 
per part of the granaries is contracted, and the aperture, 
which is that by which they are filled, is covered over by 
a stone : the grain is taken from them through a hopper 
placed at the bottom. To avoid all dampness, the space 
contained between the walls of the granaries and those of 
the rock is filled with fine and very dry sand from the 
Loire. A gallery formed also in the rock communicates 
on one side with the granaries, and on the other with a 
staircase cut in the rock, which conducts directly to the 
banks of the river. It would seem that the excavations 
served as magazines of stores for daily consumption, and 
the granaries for reserved supplies. It is difficult to con- 
ceive of any arrangement more suitable for preserving 
grain, or of a situation more favorable for obtaining or for 
transporting it. 

In some warm and dry countries, it has been customary 
from time immemorial to preserve grain, with less pre- 
caution certainly than in the granaries above described, 
but in situations where it could be kept for six or seven 
years. Prosper Alpinus relates, that not far from Cairo 
there was a high wall built, enclosing a spot of ground of 
about two miles in circumference, which was filled every 
six or seven years with heaps of wheat : he adds, that the 
abundant dews of night softened the outer portions of the 
grain and caused it to germinate, but that in a short time 
the sun dried the young shoots, which then formed a hard 
covering to the mass, and did not permit either air or 

* Des Fosses propres a la Conservation des Grains ; par M. le comte 
de Lasteyrie. 



192 CHYMISTRY APPLIED TO AGRICULTURE. 

moisture to penetrate it. In a similar manner individuals 
may preserve their grain upon floors in the open air, merely 
by covering the heaps of it with mats. 

In the Basil icata, according to the report of Intieri,* the 
farmers form their corn into heaps upon the borders of the 
sea ; these are soon covered, in consequence of the rains, 
with a strong vegetation, which forms over them a layer im- 
permeable by air or water. 

There is a curious account given by Joinville, of the man- 
ner in which supplies of provisions for the army which St. 
Louis conducted in person to Jerusalem, were secured. 

" Quant nous venimes en Cypre, le Roy estoit ja en Cypre, 
et trouvames grant foison de la pourveance le Roy; c'est a 
savoir, les celiers le Roy et les deniers et les garniers. Les 
celiers le Roy estoient tiex, que sa gent avoient fait en mi 
les champs sur la rive de la mer, gran moyes de tonniaus 
de vin, que il avoient achete de deux ans devant que 
le Roy venist, et les avoient mis les uns sus les autres, 
et que quant Ten les veoit devant, il sembloit que ce feussent 
granches. Les fourmens et les orges il les r' avoient mis par 
monciaus en mi les champs ; et quant en les veoit, il sem- 
bloit que ce feussent montaignes ; car la pluie qui avoit batu 
les blez de lone temps, les avoit fait germer par desus, si que 
il n'i paroit que I'erbe vert. 

" Or avint ainsi que quant en les vot mener en Egypte, Pen 
abati les crotes de desus a tout I'erbe vert, et trouva Ten le 
fourment et I'orge aussi frez comme I'en I'eust maintenant 
batu." t 

This method of preservation is undoubtedly less costly 
than that of dicraincr ditches ; but there is in it some loss of 

* Delia pcrfetta Conservazione del Grano ; 4 to. page 12. 

t " When we came to Cyprus, the king was already there, and we 
found great abundance of stores collected by him ; the cellars of the 
king and his treasures and granaries were as follows. The cellars of 
the king, which his people had made in the midst of the fields upon the 
borders of the sea, were three in number, stocked with great casks of 
wine, bought two years before the king's arrival ; the cellars were 
placed one over the other, so that when viewed in front they looked 
like barns. The wheat and the barley they had put in heaps in the 
midst of the fields, and these appeared like mountains, for the rain had 
moistened the corn for a long time, and caused it to germinate on the 
outside, so that nothing was seen but the green herb. 

*• Now when we had determined to carry the grain into Egypt, and 
the outer crust was removed from the heaps of grain, the wheat and 
barley were found as fresh as if but now piled up." 

History of St. Louis. Paris. 1761. folio, pp. 28 and 29. 



PRESERVATION OF FRUITS CY SECLUSION. 193 

grain, nor can the rest be so securely kept for several years 
as it would be in pits. The custom however has long pre- 
vailed, and is still to be found throughout Europe, and 
even in Asia and Africa. 

The grains which are consumed in Algiers and Tunis, 
or which are exported thence, are, after having been well 
dried in the sun, deposited in trenches cut in the rocks, 
. and havinor their sides lined with straw. The Count of 
Lasteyrie has found the same mode followed in Malta, 
Sicily, Spain, and Italy. There are even some countries 
where the governments have caused trenches to be con- 
structed, in which the cultivators of lands might deposit 
their harvest till a favorable season for selling them. 

In order to secure a perfect preservation of the grain in 
trenches, it is necessary to make use of certain precau- 
tions, without which the entire loss of it must be hazard- 
ed : the means of security are as follows. 

1st. The grain should never be put into trenches till 
it is perfectly dry ; it must therefore be first exposed to the 
sun for several days, and during that time be often turned, 
that every part of it may became equally dry. 

2d. In constructing the trenches, choice must be made 
of a dry soil, or a rock free from chinks, that there may 
be no danger either from dampness or the filtration of 
water. The walls of the trenches may be made with such 
cement as the Romans used in the construction of their 
aqueducts ; this is composed merely of lime and pebbles ; 
the walls of these aqueducts were raised in frames, and 
the surface of them carefully polished ; I have visited the 
remains of some of them in various parts of France, and 
have found them everywhere present the same appear- 
ance : I am convinced that this cement is impenetrable by 
water, and of a solidity more than sufficient for construct- 
ing the sides of trenches.* 

3d. The third precaution consists in excluding the air 
completely ; if this fluid should gain admittance, it must 
necessarily convey in at the same time moisture and oxy- 
gen, the two principles of germination ; the presence of 
air will likewise favor the existence and multiplication of 
insects ; whilst if the trench be full of grain, and well 
closed, all the air which it contains will be changed into 

* The mode of building may be used which the Count of Lasteyrie 
has proposed in his work, entitled Des Fosses pour la Conservation des 
Grains. 

17 



194 CHYiVIISTRy APPLIED TO ACRICULTtJRE- 

carbonic acid, (as T have explained in speaking of the 
action of air upon fruits,) and the insects will remain tor- 
pid. This last assertion is, as we shall shortly see, sup- 
ported by the results of the experiments which have been 
made by the Board of Provisions of War, for the purpose of 
ascertaining the best mode of preserving grain. 

But the construction of these trenches, as it involves 
some expense, and requires much care, will be for a long , 
time rejected by mere farmers. However advantageous 
this arrangement may be, it belongs entirely to public au- 
thorities, great cities, and governments, to set an example 
of the use of it, by withdrawing from circulation, during 
yerjrs of abundant harvests, large quantities of corn to be 
deposited in trenches and preserved against years of scarci- 
ty. Much has been written, within a few years, upon the 
best methods of preserving grain ; but all those that have 
been proposed were founded upon the same principles. 

The Board of Provisions of War, under the direction of 
Oount Dejean, has performed a series of well-directed ex- 
periments, from which excellent results have been obtain- 
ed : the apparatus used in them consisted of lead receivers 
hermetically sealed and having all their joinings soldered. 
Meal and fjrain full of weevils were enclosed in three re- 
ceivers ; when these were opened, at the end of a year, it 
was found that no injury had been done by the weevils ; 
they were all either dead or in a state of torpor. In one 
of the receivers there was found a collection of grains ad- 
herinff to each other in a mass about as large as a mid- 
dling-sized apple : this arose from the entrance of air and 
moisture through a hole the size of a pin, accidentally left 
unsoldered in one of the joints. 

The elder M. Ternaux caused trenches to be formed 
and filled with corn in the beautiful field of Saint Arven ; 
in order to be sure of the preservation of the grain, he 
caused the trenches to be opened from year to year, and the 
results were always satisfactory. 

Corn, well dried and guarded from air and moisture, 
may be preserved in the ear for a long time, and it is a 
well-known fact that in some agricultural countries the 
sheaves are formed into stacks which are taken down 
either for consumption or the market, at those times when 
the laborers upon the farm can be employed only in thresh- 
ing in a barn. 

Instead of constructing trenches of stone without the 



PRESERVATION OF FRUITS BY SECLUSION. 195 

farm buildings, there might be built, within them, bins of 
stone, of a size proportioned to tlie produce of the farm, 
and with the openings covered in such a manner as to ex- 
clude the air. The same purpose may be answered by 
chests and tubs of wood having their outsides covered 
with a thick coat of oil paint. The great earthen jars 
in which oil is kept at the south, are likewise very good 
for keeping grain in. 

Either of these methods is preferable to that of storing 
grain in such granaries as are commonly used, since the 
utmost care will not entirely protect it from moisture, in- 
sects, mice, &/C., nor will it often remain in them un- 
changed beyond three or four years. 

Corn which is housed without being thoroughly dried, 
or which is stored in a damp place, acquires a musty smell 
and taste, which render it unfit for the customary uses : 
but as this alteration affects only the outer covering, and not 
the substance of the kernel, it may be easily removed by 
throwing upon the grain double its weight of boiling water, 
carefully stirring the mass till the water becomes cold. 
The spoiled kernels, which swim upon the top, must then 
be removed, the water poured off, and the grain spread to 
dry. rr. Peschier preferred employing f.r this purpose 
boiling water rendered slightly alkaline, and afterwards 
washing the grain in pure water.* 

When corn has been heated or injured in a perceptible 
manner, the vegeto-animal portion is almost always chang- 
ed ; in this case the farina is not susceptible of a good 
fermentation, and the bread made from it is unwholesome : 
such grain is fit only for the manufactory of starch. 

The modes of preserving vegetable juices and other arti- 
cles of food deserve also much attention. 

The substances of which I shall now speak present the 
alimentary principle so mixed with, or dissolved in the 
aqueous fluid, as to render them exceedingly susceptible 
of alteration and decomposition. It is not sufficient to se- 
clude these from the air, since they contain for the most 
part within themselves those principles of fermentation, 
which, acting upon each other, produce decomposition. 

Seclusion from the air alone will not preserve these sub- 
stances ; the nature of some of the fermentative principles 
must be changed ; and for effecting this I would recom- 

* Annales de Cliimie et de Physique, tome VI. page 87. 



196 CHYMISTRY APPLIED TO AGRICULTURE, 

mend the preserving process made use of by M. Appert, 
and confirmed by numberless experiments. I shall here only 
make mention of the mode of preservation ; as the work of 
M Appert is before the public, it may be consulted in re- 
gard to the necessary details respecting each operation.* 

The process consists, 

1st. In putting up, in glass jars or bottles, those solid 
or liquid substances which are to be preserved. 

2dly, In corking the bottles carefully. 

3dly. In placing these vessels uprigh' in a boiler filled 
with cold water, as hio-h as the rinu of the bottles. 

4thly. In causing the water to boil, and continuing the 
ebullition for a longer or shorter time, according to the 
nature of the substance contained in the vessels. 

In this process we see that nothing more is required than a 
boiler and some bottles or jars ; it is one that may be prac- 
tised in the smallest domestic establishment. In order 
however to avoid accidents and insure success, certain 
precautions in each part of the process are necessary : the 
principal of these, especially those that are indispensable, 
I shall here point out. 

The choice of bottles is a matter of some consequence : 
the form of the champagne bottles is the best, and as the 
glass of these is of a more uniform thickness tiian that of 
others, it is generally better annealed ; these bottles then 
should be preferred, particularly if they have proved their 
soundness by having resisted the action of the compressed 
air contained in foamingr wine. 

Too much care cannot be taken in the choice of corks; 
only the superfine should be used, and these should be free 
from defects. The length of the corks should be at least 
eighteen or twenty lines, and the diameter a little greater 
than that of the mouth of the bottles, into which they must 
be forced by blows of a mallet. 

The bottles must be filled within three inches of the 
ring ; the corks selected for them must be softened a little 
in water ; in stopping a bottle, put the small end of the 
cork into the mouth of the bottle, and force it in as far as 
possible with the hand ; then wrap the bottle in a towel, 
and, holding the neck of it firmly in the left hand, drive 



* Le Livre de tons Ics Minages, ou UArt de conserver pendant 
flusievrs annces toutes Ics Substances Animates et Vigitales. 1811, 
2^ edition ; par M. Appert. 



PRESERVATION OF FRUITS BY SECLUSION. 197 

the cork in by repeated blows with a mallet ; a few lines 
of the length of the cork must be left beyond the mouth 
of the bottle to receive the wire or twine with which it 
is to be secured. Each bottle is then to be put into a 
bag of strong linen, which will cover it to the cork, and 
placed in a boiler filled with water to the rings of the 
bottles. The boiler is to be covered, and over the lid 
must be placed a damp linen cloth, to secure the retention 
of the heat. The apparatus being thus prepared, the 
water may be heated to boiling, and continued in that state 
as long as the nature of the substance to be preserved 
requires. 

When the fire has been removed from the fire-place a 
quarter of an hour, the water must be drawn off by means 
of a siphon, or of a stop-cock placed near the bottom of 
the boiler ; the cover must not be removed to take out the 
bottles till fifteen minutes after the water has been drawn 
off.* 

When meat or other solid food is to be preserved, wide- 
mouthed bottles or jars may be used in the same manner 
as the narrow-necked bottles mentioned above. Good 



[* The translator of this work has preserved the most delicate fruit 
by a process somewhat similar to the one here described, but with one 
pretty important difference. As the preservation of the fruit seems 
to depend wholly upon the exclusion of the air, which would not be 
effected by corking the bottles before exposing them to heat, and as 
the bottles would be in great danger of being burst by the expansion 
of the air contained not only in the fruits themselves, but in the 
interstices which must unavoidably occur between them, the above 
method appears to be an imperfect one : she therefore takes the liberty 
of inserting in this note the process which she has used successfully, 
and particularly as she has found fruit thus preserved exceedingly 
grateful in sickness at those seasons of the year when no fresh fruit 
could be procured, and when that which was done with sugar waa 
neither suitable nor agreeable. 

Pick carefully over the fruit to be bottled so as to take only such 
as is perfectly sound, and put it in bottles having wide mouths with 
closely fitting corks, shake the fruit well down so as to leave as little 
space unoccupied as possible in the bottles ; when they are quite full, 
set them uncorked into a boiler of cold water over the fire, raise the 
temperature of the water as quickly as possible to the boiling point, 
and as soon as ebullition takes place, put the corks into the bottles, 
and remove them from the boiler ; some ready melted cement, 
such as is commonly used for closing bottles, must be immediately 
applied over the corks, and the fruit having been freed by the heat 
from the air contained within the bottles will thus be protected from 
the action of- the external air. and may be preserved fresh for many 
months. — Tr.] 

17 * 



198 CHYMISTRY APPLIED TO AGRICULTURfi. 

gravy of meat, and beef three quarters cooked, when pre- 
pared according to the foregoing directions, have been 
found as good after being eighteen months at sea, as vi'hen 
first put up. Attention must be paid in putting up solid 
articles in bottles, to pack them closely, in order that as 
little air as possible may interpose between the pieces. 
Consommes, strong decoctions,* and jellies of meat con- 
taining all those portions of it most nourishing to man, 
may be thus preserved uninjured for a long time. 

Before milk is put into bottles for keeping, it should be 
evaporated in a water or vapor bath, and the scum which 
forms upon the top carefully removed ; half an hour be- 
fore evaporation is completed, there should be mixed with 
every pint of the reduced milk, the yolk of an egg well 
beaten. After being thoroughly cooled the milk must be 
put into bottles, and corked tightly, to undergo the second 
scalding. Milk preserved in this way has been found at 
the end of two years to be unchanged, and to afford butter 
and butter-milk the same as if new. It is not however 
pretended, that it preserves all the qualities of new milk; 
it almost always has a peculiar odor and taste, but such 
as it is, it forms an agreeable and a valuable article for sea 
stores for long voyages. 

Cream evaporated one fifth part and put into bottles 
after having had the skin coagulated upon the surface re- 
moved from it, and then subjected to a second scalding 
for an hour, has not been sensibly altered at the end of two 
years. 

Those vegetables of which so much use is made in all 
families, may be preserved in the same manner ; they are, 
however, boiled a shorter time, and some of them must 
previously undergo a degree of preparation. For instance, 
in preserving asparagus it is necessary, after having wash- 
ed it, to plunge it first into boiling and then into cold water, 
to deprive it of its acrid taste ; it afterwards receives but a 
slight scalding. 

To preserve the color of the small bush-beans, bottles 
filled with them are plunged into very cold water, where 
they remain for an hour ; they are then drawn out, corked, 
wired, and scalded for an hour. Artichokes, after having 
had boiling water poured over them, are washed in cold 
water, drained, and scalded in the bottles for an hour. 

* Answering to " portable soups." 



l*RESERVATlON OF FRUITS BY SECLUSION. 199 

Cauliflowers are prepared in the same way as artichokes, 
excepting that they are boiled but half an hour. Legumes 
in general, prepared and seasoned, and put into bottles 
when three quarters cooked, will keep very well with being 
scalded twenty minutes. 

Antiscorbutic plants, and the juices which are extracted 
from all fruits and vegetables, require only to be scalded. 
When juices are to be kept, they should be carefully 
strained and clarified ; plants require to be well washed, 
picked and dried, and to be crowded into the bottles. 
When any of these preparations are made use of, they 
should be dressed in such a manner as to give them the 
appearance of those prepared daily in our kitchens. 

Those articles that have been cooked before being put 
*nto bottles, only require to be heated. 

The strong decoctions will need the addition of nothing 
but water to become good broth. 

The jellies of beef, veal, mutton, chickens, &lc., when 
diluted with water, and seasoned with salt, make excellent 
soups. 

The legumes must be washed upon being taken from the 
bottles, and then prepared as if fresh. 

The juices may be appropriated as usual, either for food, 
drink, or medicine. 

I shall close this article by observing, that some bodies 
are preserved from destruction, and guarded from the at- 
tacks of insects, and the action of air and water, by 
means of a coat of varnish laid upon the surface of them ; 
this practice has become very common, and when the 
varnish is applied to bodies well dried, and does not scale 
off, it preserves them a long time. Oil paints and tar pro- 
duce the same effect. 

The custom of preserving eggs by immersing them in 
lime water has lately been introduced into Paris ; the 
shell of the egg thus immersed becomes covered with a thin 
coat of lime, which preserves its contents unchanged. 



200 CHYMISTRY APPLIED TO AGRlCULTtTREf^ 



ARTICLE IIL 

On the Preservation of certain Articles of Food by means 
of Salt and Spirituous Liquors. 

Most of the articles employed as food, or other domestic 
purposes, may be prepared by the following methods, 

1. By immersing them in liquids which will not dissolve 
them, and which will not themselves be changed by time. 

2. By combining them with other bodies with which they 
form indestructible compounds. 

8. By saturating them with salts. 

In the first method the liquor usually employed is either 
alcohol or brandy ; many other fluids, as the acids, 
oil, &/C., might be made use of, but these alter the taste, 
and change the qualities of the greater part of the sub- 
stances, which are designed for food. Nearly all kinds 
of fruit may be preserved in alcohol, but it is used only 
for those of small size, as it cannot penetrate throughout 
the substance of the larger kinds, and consequently they 
are liable to decay ; I shall therefore mention only the modes 
of preserving cherries and plums in brandy. 

The juice of six pounds of early and very ripe cherries 
put into a sauce-pan, with three pounds of powdered 
sugar, is set over a fire and made to boil for half an hour ; 
the sauce-pan is then removed from the fire, and a pound 
of ripe raspberries is thrown into the liquor and pressed 
down with a skimmer ; to the whole is added six pints of 
brandy flavored with some aromatic, such as cloves, cinna- 
mon, vanilla, &c. This preparation is preserved in close 
jars set in the sun. 

As soon as the large cherries are ripe, the preparation 
of brandy, mentioned in the last paragraph, is to be strain- 
ed and then put into glass jars filled with the fruit to be 
preserved ; these jars are placed on windows exposed to the 
sun, till the fruit becomes penetrated by the liquor. 

Plums are prepared in a somewhat different manner. For 
preserving, take the finest green gages, prick them, and 
put them into a sauce-pan with cold water ; set the sauce- 
pan on the fire, and as fast as the plums rise, remove them 
with a skimmer, and throw them into cold water ; dissolve 
two pounds of sugar in two pounds of hot water, and 
when the sirup is cold, throw the plums into it, and allow 



TRESERVATION OF FOOD BY MEAXS OF SALT, &LC. 201 

them to remain in it at a gentle heat for some time ; 
when the fruit is penetrated by the sugar, remove it, 
evaporate the sirup, put the fruit again into it, and treat 
it as before; after which, remove it again, and evaporate 
the sirup till it becomes tenacious, then return the plums 
to it for the last time. When the whole is cold, put it into 
bottles with a quantity of brandy equal to that of the 
plums and sirup. The unbroken plums alone must be put 
up in this way. 

The description of this process is a sufficient guide for 
those, who wish to preserve other fruits in the same way. 

When sirups are used instead of sugar, a greater quantity 
of brandy than that mentioned is necessary to preserve the 
fruits unchanged. 

Alcohol dissolves and retains the aroma of plants ; it is 
only necessary to make an infusion of the plant or flower 
in alcohol, and afterwards to pass the liquor through a 
filter, 

I do not hesitate to direct in this work certain methods 
of obtaining spirituous liquors, which, when used sparing- 
ly, appear to me to be serviceable in preserving the health 
of country people. I feel that I ought not to aim at giving 
these drinks the qualities required by the luxurious, and 
those of delicate and refined taste, but direct such methods 
of obtaininor them as are consistent with the most riorid 
economy, and with the employment of such materials as 
every mistress of a family has within her control. 

To make three pints of ratafia of nuts, crack two hundred 
apricot stones from which the pulp has been separated; 
spread the kernels in the sun, and after they are sufficiently 
dry, pound them in a mortar, and put them into a bottle 
with a quart of brandy ; cork the bottle carefully and set it 
in the sun. After twenty days, strain the liquor and add to it 
a pound and a half of sugar dissolved in half a pint of 
water, or two pounds and a half of good sirup ; if a portion 
of almonds be mixed with the apricot kernels, the flavor of 
the liquor will be improved. 

Some ratafia is made of almonds alone ; in this case the 
kernels are thrown into boiling water to deprive them of 
their outer skin ; they are then bruised in a marble or 
wooden mortar, with a little water and sugar, and this 
paste is put into a bottle with brandy ; after having been 
exposed several days to the sun, the liquor is strained, and 
a suitable portion of sirup added to it. Very good ratafia 



202 CIIYMISTKY AIMM.IKD TO AGRICULTURE. 

is mado from almonds and the kernels of peaches pounded 
together. 

The base of all luiiiors of tliis kind is brandy and sajjar ; 
the dirterencc in their flavor arises from the aroma and other 
portions of vegetables incorporated with them. 

The best mode of proceedinjr is, to prepare first a licjiior, 
by dissolvinjir eii^ht pounds of sufrar in three linies its weight 
of water ; this must be boiled and skimmed, and when all 
the sugar is dissolved, the li(juor muJit be strained and put 
into a jug with ten pints of brandy, the jug carefully corked 
and set in a cool place. Into this licpior various substances 
calculated to gratify the taste and smell may be put ; when 
a portion of it is to be used, it is to be poured into a sauce- 
pan, and after being slightly warmed, the flavoring designed 
for it is to be added. 

For orange-flower water, make an infusion of the petals 
of the flower, filtrate it through paper, an<l add of sugar one 
eighth of the weiixht of the flowers. 

When the liquor is to be flavored with citron, orange, 
bergamot, or lemon, the surface of the fruits may be grated 
with bits of sugar, which imbibe the volatile oil contained in 
small vessels in the rind, and the sugar thus saturated with 
aroma is dissolved in the liquor. Vanilla, cinnamon, and 
clove may be used for the same purpose. 

Liquors are sometimes made with the juices of fruits well 
refined. 

1 will here give as an example the ratafia o{ four fruits. 

After having expressed the juice from ten pounds of 
cherries, and as many of currants, five pounds of raspber- 
ries, and five pounds of black currants and of bitter cher- 
ries, add to each pint of the juice one pint of good brandy, 
and allow it to remain undisturbed twentv-four hours ; at 
the end of that time strain the liquor and add to each pint 
of it eight ounces of sugar; six weeks after, the li(juor must 
be again strained, and an additional flavor may be given it 
if desired, by adding to it a little cinnamon, or clove-water, 
pounded coriander seeds, or bitter almonds. 

All animal substances may be j)r(^served from j)utrefac- 
tion in alcohol ; anatomical jirej)arations and some entire 
animals are kept in this liijuid ; but it is necessary that 
the alcohol employed for this purfw.se be of the best kind 
to be found in commerce ; if it should contain any con- 
giderabh' projHjftion of watery j)articles, those j)ortions 
of aniujal matter which are soluble would be dissolved 



IPRESERVATION OF POOD BY MEANS OP SALT, &,C. 203 

and corrupted. Care must likewise be taken that the jars, 
in which these substances are put, be hermetically sealed, 
as otherwise the alcohol will be lost by evaporation. 

There is another way in which animals of a small size 
may be perfectly preserved by means of alcohol ; of this I 
am convinced by some experiments which I have made 
with the most satisfactory results, upon birds, in the fol- 
lowing manner. Having suspended the bird by the beak, 
the vent being secured by a thread, I fitted a little tunnel 
to the throat, and thus filled the crop and intestines with 
very pure alcohol ; as soon as this was evaporated, I poured 
in a fresh portion, and repeated this till the flesh was as 
dry as tinder. In this way the form of an animal may be 
perfectly preserved. 

The second means of preservation of which I spoke at 
the commencement of this article, consists in bringing 
these substances into union with such bodies as will form 
with them indestructible compounds. The conversion of 
skin into leather is the most striking instance I can bring 
of this process : this is done by causing the tannin of 
certain vegetables to combine with the gelatine, which 
forms nearly the whole substance of skin : from this union 
there results a hard, indestructible compound, preserving 
the original form of the skin, but with increased weight. 

The third mode of preserving bodies, is to incorporate 
them with salts unalterable by the air, which, penetrating 
the whole tissue of the substance, prevent decomposition: 
this is the most valuable and generally practised method of 
preserving meat and fish, and the articles thus prepared 
form an extensive branch of commerce between different 
nations ; a supply of food which would otherwise be want- 
ing, is thus provided. 

The best salted provisions were formerly furnished by 
Ireland, and that country still carries on a very extensive 
traffic in them, though the same methods practised there, 
have been adopted by the Danes and other nations. I shall 
heie describe succinctly the modes made use of* 

For salting, the fattest oxen of from five to seven years 
old are chosen ; before that age, the flesh has not sufficient 
firmness, and after that period, it is too hard. 

When the animals have been driven from a distance,^ 

* The fullest statements may be found in the work of M. Martfelt, 
translated frorrtthe Danish, by M. Bruun-Neergaard. 



204 riiY.Mij<rRY applied to agriculture. 

they lire not killed till two days aftor tlieir arrival, and in 
tho iiitorval arc allowed oidy water : before being killed, 
they should he bled freely, that all the blood may bo drawn 
out of the body ; and even after using this precaution, it is 
necessary, when the meat is cut up, to remove the blood 
very carefully from the pieces. 

The carcasses should not be cut up till the animals have 
been dead twenty-four hours, and when this is done, all the 
marrow must be carefully removed from the bones. 

The salt emj)loyed should be pertectly clean, and of a 
fine and heavy kind : the fine salt of Portugal is esteemed 
the best. 

Th(? proportion of salt to meat should be in volume, as 24 
to 100. If oidy the Lisbon salt be used, the proportion is 
as 2 to 7i : in general the proportion in weight is as 1 of 
salt to () of meat. 

That the salt may penetrate the meat quickly, the salters 
have a leather guard or a glove shod with iron upon the 
right hand ; this glove is composed of two or three pieces 
of sole-leather, united by nails with rough, broken heads; 
a strap of leather serves to keep it on, and it thus forms a 
sort of flesh-brush, with which the blood can be ])ressed 
out of the meat, and the salt rubbed into it. Each piece 
of meat passes through the hands of a series of salters, 
who execute upon it the same operation, and when it arrives 
at the last, who is the most experienced and skilful, he 
examines to see if there be any defect in it, any vein which 
requires to be opened ; he corrects the defects, opens the 
veins, rubs in more salt, and throws it into the cask of 
salted pieces : in this it remains in the air eight or ten 
days, the salt penetrates into it, and is turned into brine : 
at the end of this tiuie it is taken out and barrelled. Afier 
the meat is removed from the cask, the brine is thrown into 
a trough, and a layer of salt put at the bottom of the cask; 
ujKm this is jdaced a layer of meat, and thus alternately 
till llu! cask is full. Attention must be j)aid to j)ultiug the 
pieces of inferior (piality at the bottom of the cask, those 
of the better kind in the middle, and the best at top. When 
the meat is all packed in, it must be pressed down with a 
weight of fifty pounds, and the cask closed. 

There must afterwards be a hole bored in one end of the 
cask, to blow into, in order to be sure that it does not leak : 
if no air escapes, the hole is closed again : if the contrary 
be the case, the aperture through which it passes is sought 



PRESERVATION OF FOOD BY MEANS OP SALT, 6lC. ^205 

for. When it is ascertained that the cask is in good order, the 
bung is taken out, and the brine turned in till the meat is 
saturated and covered : the less brine is required, the better 
will the meat keep. 

After having allowed the barrels to remain five days, it is 
necessary to examine whether they are well filled with brine, 
and if not, it must be added till they can contain no more : 
they must then be again blown into to be certain that they 
can lose none, and then the operation is ended. 

Tongues are salted in separate casks. 

The manner in which pork is salted does not differ from 
that which I have just described as used for beef, excepting 
that the fat is rubbed less. 

In Hamburor the art of smoking beef has been carried 
to a degree of perfection not attained elsewhere ; and the 
smoked beef of Hamburg enjoys everywhere the highest 
reputation. 

For this purpose the fattest cattle of Jutland and Holstein 
are preferred, and these must be of a middling age. The 
meat is salted with English salt ; the stronger salts, as those 
of Portugal, deprive the meat of its natural taste, and as the 
process of smoking contributes to preserve it from injury, 
that of salting does not require so much care. 

To preserve the red color of the meat as much as possible, 
a certain quantity of salt-petre is added to the English salt, 
and the meat is allowed to remain in it eight days before 
being smoked. 

Fires of oak chips are built in cellars, from whence the 
smoke is conveyed by two chimneys into the fourth story, 
and thrown into a chamber by two openings placed the one 
opposite the other. The size of the chamber is proportion- 
ed to the quantity of meat to be smoked, but the ceiling is 
not raised more than five feet and a half from the floor. 
Above this chamber there is another made of boards, into 
which the smoke passes through a hole in the ceiling of the 
first, whence it escapes by openings formed in the sides. 
The pieces of meat are hung up in the first chamber, at the 
distance of a foot and a half from each other, and a fire is 
kept up night and day for a month or six weeks, according 
to the size of the pieces. 

The sausages are suspended in the second chamber, and 
the largest of them allowed to remain there six or eight 
months. 

In this process two means of preservation are combined : 
18 



'206 CHYMISTRY APPLIED TO A(.RICULTLKE. 

the first is the action of salt, and the second that of the 
pyrol igneous acid, wliich is furnished by combustion, and 
which constitutes by far tho irrejitor part of snjoke : this 
acid, as I liavc found by repeated experin)cnts, penetrates 
the meat and preserves it from putrefaction, but when em- 
ployed alone, the meat becomes hard, and ac(juires a disa- 
greeal)le blackish hue. 

Animal substances, by being immersed in a weak acid, 
or in water acidulated with sulj)huric acid, may be preserved 
a long time without undergoing putrefaction, but this process 
is not apj)licablo to such as are designed for food. 

Other salts may be employed as substitutes for marine 
salt ; but besides being more* costly, they are either injurious 
to the health, or give to the meat a disagreeable taste, of 
which it cannot be entirely deprived. 

Butter is a valuable article of food, and forms a great re- 
source for the inhabitants of the Country ; but in those re- 
gions where the extent and fertility of the pasture lands per- 
mits great numbers of horned cattle to be raised, it is im- 
possible for them to consume all the butter they make, whilst 
it is fresh ; and besides, as tht; (juantity of butter made is 
not the same at all seasons of wie year, it is necessary that 
some means should be resorted to of preserving it from be- 
coming rancid, and this is done by salting it. 

The choice of a kind of salt suitable for preserving but- 
ter is not a matter of less importance, than when it is used 
for salting meat. Only such should be used as has, by long 
exposure upon the edges of the salt-pans, lost all the deli- 
quescent salts which combined with it ; salt in this state is 
drier and purer, than the new salts extracted by cvajwration 
from sea-water, and has neither the sharpness nor the bit- 
terness which characterize these. But whatever salt is 
used, it is advisable that it be whitened and j)urified by the 
process commonly made use of in our kitchens; it must be 
dried in an oven, and afterwards pounded in a marble or 
wooden mortar. 

Nothing more is requisite in salting butter, than to work 
it well, so that the salt may be equally distributed, and then 
to put it down in clean and dry stone jars. If it should be 
perceived, seven or eight days after, that the butter has 
shrunk so as to leave a vacancy around the sides of the 
pot, a brine must be prepared by saturating hot water with 
pure salt, and this when cold nnist be turned gradually 
U|)on the butter till every part of it is well covered : the 



OF MILK AND ITS PRODUCTS. 207 

pots are then to be set in a cool place till the butter is taken 
out and made into lumps for market or home consumption. 

Another way in which butter may be preserved a long 
time, is, by melting it in a pot at a very low degree of heat, 
skimming from the surface a thin layer of curd which will 
form upon it, and when this no longer collects, withdrawing 
it to cool and harden. 

When the juices of fruits are to be preserved for food, 
sugar is used instead of salt ; this possesses the double ad- 
vantage of correcting the acid of fruits, and of incorpo- 
rating better with them. Sugar improves the quality of the 
juices as much as salt would injure them, and as this last 
cannot be extracted, they could not be used as articles of 
nourishment. 

The preparations formed with sugar are jellies and sirups ; 
the first are the most concentrated, and serve as food ; the 
latter mix easily with water, and are generally employed as 
drinks. 

After the juices are expressed, clarified, and strained, 
there must be added to them a suitable portion of sugar : 
most of them require an equal weight : they must then be 
boiled gently till sufficiently evaporated, and the operation 
completed by clarifying the liquor, which is thus rendered 
more agreeable to the eye. 



CHAPTER XI. 

OF MILK AND ITS PRODUCTS. 



There is no product of a farm which contributes more 
towards the prosperity of the establishment than milk; 
not only does it form in itself one of the most important 
articles of food for the family, but the sale of a portion of 
it, either in its natural state, or made into butter or cheese, 
furnishes a daily income, from which nearly all the inter- 
nal wants of a household may be supplied : I therefore 
think it will not be departing from my subject to devote 
one chapter in this work to an object of so much impor- 
tance. Milk appears to me to be one of the least animal- 
ized portions of the animal kingdom. The various kinds 
pf food taken by animals affording milk, give to it various 



208 CllYMIsmV APPLIED TO AGRICULTURE. 

degrees of richness and diftbrent tastes : the milk of a cow 
which is fed upon the leaves and stalks of maize, or upon 
the rofiiso of beets, is very sweet, and that of a cow nour- 
ished with cahbacros has not so sweet a taste, and exhales a 
disairreeable odor ; the milk of cows which browse damp 
mea«i()ws is watery and insipid : from these facts we may 
establish as a princii)l(', that the quality of milk may be so 
vari<'d by the choice of fcKxl, as to adapt it to the wants of 
the indiviilual to be nourished by it, whether he be a healthy 
man or a!i invalid. 

The numerous experiments that have been made by Messrs. 
Deyena and Parmenticr to ascertain the effect of Ibod upon 
the milk of a cow, furnish the following results : 

1st. That it is improper to chani;(; suddenly the kind of 
food, as it for a time diminishes the (juantity of inilk, even 
though the food be more succulent and of a better kind. 

*2nd. That all ])lants do not give to milk their characteris- 
tic qualities, and that there are some tiiat do not exercise 
any particular action ujK)n either of the constituent princi- 
ples of milk. 

By distillincr milk in a water-bath there is obtained an ex- 
tract of limpid liquor of about \ the weight of the milk em- 
ployed, ha\ lug the odor peculiar to milk, and containing a 
putrefiable aiiimal substance which gradually lenders the 
color of the extract cloudy, and its consistence viscid ; this 
substance becomes putrescent in a longer or shorter time, 
according to the nature of the food upon which the animal 
atfording the milk is nourished. 

This first distillation does not change the nature of the 
constituent |)rinciples of milk ; they remain in an oily mass 
of a sweetish taste, and a yellowish while color. 

Butter and cheese are the two principal elements of which 
milk is composed ; the cream which is sei)arated from the 
milk, and from which a most profitable j>roduct is obtained, 
contains only one of them, butttT, which is the most im|K)r- 
tant part of the cream, and is obtained from it by a very sim- 
ple process : tlie whey which remains after the biitter and 
cheese have been separated from the cream, contains in so- 
lution some salts, and serves as a vehicle or dissolvent for 
ail the c^tnstituent prlMci|)lrs of milk. 

The prin(ii>l('s contaim-d in nulk are not united by a pow- 
erful alfmity ; when milk is allowed to remain at rest, the 
butter becotnes disengag(Ml and rises to \\\v toj), where it 
forms a layer in which it is found mixed with some milk ; 



CREAM. 200 

it is this layer which is known under the name of cream. 
In this state the particles of butter have but a feeble cohe- 
sion, and still retain in combination a portion of milk which 
is by churning completely separated from them, when they 
appear with all their characteristic qualities. 

As the preparation of these two products of the same fluid 
present different phenomena, I think it best to treat of them 
under different heads. 



ARTICLE I. 

Of Cream. 



The surface of milk which is allowed to remain undis- 
turbed in a cool place, becomes covered with a thick, unc- 
tuous substance of an agreeable taste, and usually of a 
yellowish white color ; this substance is called cream. The 
first layer which is formed is not very close, but as the but- 
ter ascends, the coat increases in density ; when it can, by 
pressing it with the finger, be removed without disturbing 
the milk, it is time for it to be skimmed off. Twenty-four 
hours, with a degree of temperature equal to 59° of Fahren- 
heit's thermometer, is sufficient for raising the cream : but 
at a higher temperature the cream forms more quickly, and 
has less consistency ; it may then be removed in twelve 
hours. Cream is much better either to be used in that state, 
or for churning, than when it is allowed to remain a longer 
time upon the milk. 

Cream should be kept in a cool place, and in jars with 
narrow openings closely covered, so as to exclude the air, and 
to keep it from being affected by the variations of tempera- 
ture in the atmosphere. 

From experiments recently made, we ascertain, that the 
larger the surface presented to the air by milk is, the more 
rapidly is the cream separated, and that a degree of heat 
equal to from SO'' to ^5>° Fahrenheit, is the most favorable 
to this separation. 

As the abundance and the quality of cream depend almost 
entirely upon that of the butter, which constitutes nearly the 
whole of it, I shall refer to the following article the remain- 
der of what I have to say upon this subject. 
18* 



210 



CIIYMISTRY APPLIED TO A(iRICULTDRE. 



ARTICLE II. 

Of Butter. 

X HAVF. already romarkod, tliat tliore exists between the 
constituent principles of milk l)ut a very feeble atrniity: 
rest alone is sufficient to produce the separation of them 
in the course of a few hours, when tlie butter which exists 
in very minute particles in the milk, rises to the surface with- 
out any approach towards forming a solid body. In order to 
bring butter into a solid state, it is necessary to disengage 
from it all the other principles which it carries with it : this 
is done by means of churning. 

It has l)een clearly proved that the quantity of butter pro- 
duced from the milk of a new milch cow, is less tlian is 
yielded by the milk of the same cow five or six months after 
calving. It is likewise well known, that if cream be re- 
moved as fast as it is formed, the butter made from the first 
layers will be more delicate than that from the last. Milk 
that has remained a long time in the udder, furnishes more 
butter than that which is drawn as soon as it is secreted : 
thus milk that is drawn from a cow but once a day, will yield 
one seventh more of butter. 

Milk obtained at the same milking presents similar differ- 
ences; th(^ jv>rtion which is drawn first, is thirmer and more 
watery than the last drawn, and it yields less butter. 

All these facts, ascertained by experiment, are capable 
of being extensively applied both in medicine and rural 
economy. 

The particles of butter contained in cream, cannot be 
separated from the milky }>ortions with equal ease, at all 
seasons of the year, or at all degrees of temperature ; the 
operation of churning requires much more time in winter 
than in stimmer, nor can the process be shortened except- 
ing by env(l()j)ing the churn in a hot cloth, or by plunging it 
into hot water ; hot milk is sometimes added to the cream ; 
but all these means affect more or less the good qualities of 
the butter. 

Durirjf]: the heat of summer, it is necessary to set the cream 
in a cool place, aiid to churn at those hours of the day that 
are coolest ; in some countries, it is cu.stomary to place the 
churn in very cold water. 

The butter made in some countries, and which is thought 



BUTTER. 211 

to be of the best kind, is yellow, and, to deceive consumers, 
artificial means are had recourse to elsewhere, to give this 
product the same appearance. For this purpose the flowers 
of the marigold are put into stone pots, where they are allow- 
ed to macerate for several months, till a thick liquor is 
formed ;' this is strained through a cloth, and set by for use. 
Saffron flowers, roucou (annotto) boiled in water, the juice 
of yellow carrots, &c. are employed for the same purpose. 
Whatever coloring matter is made use of, it is put into 
the cream before churning, and in so small a quantity as not 
to influence, in any degree, the taste or wholesomenessofthe 
butter. 

The milk of all the various animals that has been subject- 
ed to experiment, contains the same principles ; there is found 
no difference excepting in the proportion, consistency, and 
quality of the products. 

The principles contained in milk are more easily separa- 
ted in that of the cow, than in that of any other animal, and 
it is of this that the grreatest use is made both for butter and 
cheese. 

The milk of the sheep furnishes a large proportion of but- 
ter, but it never has the consistency of that from cows' milk ; 
it is oily, and, unless very carefully washed, soon becomes 
rancid ; it is more easily melted than the butter from cows' 
milk. It is difficult to curdle this milk ; the caseous mat- 
ter remains always in a viscous state ; its taste is sweet 
and agreeable. 

Goats' milk has more consistency than cows' milk ; it is 
distinguished by a peculiar odor, especially at certain sea- 
sons : the cream which rises upon this milk is always very 
thick, and the butter made from it is uniformly white. It 
may be kept free from alteration a longer time than other 
milk : it is richer in caseous matter than any, excepting that 
of the sheep, but contains less butter than either cows' or 
sheep's milk. The slightly viscous character of the caseous 
matter, and its peculiar taste, render it excellent for making 
cheese. 

There is no kind of milk, of which different examinations 
of the products afford such different results, as that of wo- 
man : not only does the milk of different individuals present 
very diflferent results, but that of the same nurse, when an- 
alyzed at various times, offers unlike proportions of the prin- 
ciples : this has been ascertained by the experiments of 
Messrs. Deyeux and Parmentier. This milk, like any other, 



21'2 ClIYMISTRY APPLIED TO AGRICULTURE. 

becomes covered with a coat of cream, l)iit it is often the 
case, that tlie most j)rolongecl churning cannot produce any 
buttrr from it. Urpcatc^d fXjH'rimciits have proved, that the 
caseous m;itter in this kind of milk increases with the hipse 
of time from the lying in ; and that this is so feebly dissolved, 
as to become separated into very fmely divided molecules at 
a temperature of (>S° Fahrenheit: this sul)stance has always 
some viscosity, and is never dry and (juivering like that of 
cows' milk. 

Tiie astonishing diflerenccs which appear in woman's 
milk may be attributed to the passions of the mind, to ner- 
vous agitation, and to fre(iuent changes of diet. The action 
of the two tirst agents is of the most powerful kind, and as 
they are exercised most vigorously and fre(juently ujK)n the 
human species, it is not astonishing that they should e.xert a 
decided influence upon the milk of women. These observa- 
tions deserve great attention from all who are interested in 
nursing children. 

The milk of the ass bears a strong resemblance to that of 
woman ; it tlirows up a cream wliich is neither thick nor 
abundant, and from wliich there may be extracted, though 
not without dilficulty, a small quantity of soft, insipid, white 
butter, which easily becomes rancid. 

Neither woman's nor asses' milk aflbrds so much caseous 
matter as th.at of the cow or sheep ; what is obtained is more 
viscous, and possesses but a slight degree of adherence to 
the srrum. The resemblance of asses' milk to that of wo- 
man has caused it to be used in those cases, where it was 
necessary to employ a mild diet. It possesses the advantage 
over the last, of not varying so nmch in its ([uality and con- 
sequently in its effects. 

The fluidity of mare's milk is le.ss than of the two last- 
mentioned kinds, and its taste is less sweet ; it furnishes 
some cream, but it is diflicult to procure butter from it ; it 
contains but little caseous matter, and in all its products 
bears a resemblance to the milk of the human female and 
of the ass. 

From the foregoing statement we perceive that the ru- 
minating animals afford similar kinds of milk, and that 
this milk possesses peculiar and distinguishing charac- 
teristics : all the kinds contain the same principles, but 
these princi|)les vary in projKDrtion, quantity, consistency, 
and taste. 

The difference existing amongst the several kinds of 



BUTTER. 213 

milk greatly influences the products obtained from them; 
but if they be rightly mixed together, the qualities of one 
kind may serve to correct the faults of another, and thus 
more valuable products may be procured from the combi- 
nation of two or more kinds than could be had from either 
separately. 

The process of churning unites into one mass all the 
particles held in solution by milk, and brought into a some- 
what more condensed state in cream ; but there still exist 
in butter some milky particles, which cause it to undergo 
a change : to avoid this, it is necessary to free the butter 
carefully from milk. When butter is made from fresh 
cream, and is to be immediately consumed, nothing more 
is done to it than to work it over carefully with the hand, 
till all the milk is expressed from it , it then retains all the 
sweet and agreeable flavor of cream : but when it is to be 
kept for any length of time, it is necessary that it should be 
kneaded with cold water, till the liquid runs ofl" free from 
milkiness. 

All the operations required to bring cream into complete- 
ly-made butter, should succeed each other without delay ; 
for the milk expressed from butter made of cream which 
has remained too long a time upon milk, or in the churn, has 
a vinous taste. 

The less care there is taken to free butter from the butter- 
milk, the sooner will it become rancid ; in order therefore 
to preserve to it all the qualities of fresh butter, it should be 
carefully washed and kneaded : it must likewise be kept in 
a cool place, or under cold water that can be frequently 
changed : it is sometimes melted at a low temperature, and 
allowed to remain in this state till all the watery particles 
contained in it are evaporated. I have, in a former place, 
spoken of the method of salting butter ; this is the surest 
means of preserving it. (See Chap. X.) 

According to the experiments of Messrs. Deyeux and Par- 
mentier, the rancidity of butter arises from its combining 
with oxygen when exposed in contact with the air : butter 
absorbs about ^ of its volume of oxygen, and acquires from 
the union a strong, acrid, disagreeable taste. 



214 CHYMISTRY APPLIED TO AGRICULTURE. 

ARTICLE TIL 
Of Caseous Matter. 

When milk has been skimmed, if it be afterwards heat- 
ed to any detp-ee short of ebullition, there form uj)on the 
surface pellicles which gradually ac()uire some degree of 
consistency, and which may be easily removed : by con- 
tinuing the heat these may be renewed, till at length the 
milk can furnish no more of them : in this state milk can 
be boiled without occasioning any of that violent swelling 
and rising which is so hard to check, and which causes 
the boiling of this liquid to be so troublesome ; but then it 
will contain neither butter nor caseous matter : the butter 
has been separated in removing the cream, and the pelli- 
cles are the caseous matter : what remains after these two 
operations is only whey, holding in solution some kno^vTl 
salts. 

I have already remarked, that these pellicles form only in 
contact with the air ; they do not appear when milk is boil- 
ed in closely-corked bottles : the production of them may be 
accelerated by the passage of a current of air over the sur- 
face of the milk. 

The caseous matter may be separated frojii skimmed milk 
by exposing it to a gentle heat, when it assumes the form of 
a soft, quivering mass ; this is called curd : two or three 
days' exposure to a heat of from G8° to 77° Fahrenheit is 
sufficient to produce this effect. 

As the caseous matter adheres but slightly to the serum, 
and to the salts which are contained in it, it can be sepa- 
rated by means of a great variety of ditTerent bodies : it is 
to the action of some one of these that recourse is had for 
coagulating milk. 

Acids of all kinds coagulate skinnncd milk very quickly; 
the change takes place more or less rapidly according to 
the strength of the acid rmj)l()yed ; if a larger quantity be 
used, the curd is injured by retaining the taste of the acid. 

The salts which contain an excess of acid, as the cream 
of tartar, and the salts of s^jrrel, produce the same effects, 
but tlir coagulation is not complete unless the milk is near 
boiling when the salts are thrown into it. 

The rapidity witli which the sulphates coagulate milk is 
very reruarkalile : the action of these is most energetic ujK>n 
boiling milk. 



CASEOUS MATTER. 215 

Alcohol speedily precipitates the caseous matter under 
the form of fine molecules, at the bottom of the vessel. 

Very acid plants and the flowers of some vegetables, 
such as the artichoke and the thistle, curdle milk : these 
are usually employed by infusing them in cold water, and 
their action upon warm milk is very powerful. 

The substance however which is most generally used is 
a portion of the milk curd which is found in the stomachs 
of young calves that have been killed before they were 
weaned. The use which is made of this substance has 
given it the name of rennet *^ This substance is prepared 
for use in the following manner. The membrane of the 
stomach of a young and newly killed animal is opened, and 
the coagulated milk is taken out, washed with cold water, 
dried with a linen cloth, salted, and returned into the mem- 
brane ; this is suspended in a dry place that the rennet 
may be freed from moisture : the rennet may afterwards be 
used by mixing a little of it in milk, and then throwing the 
liquid into the milk which is to be curdled. 

The quantity of rennet necessary to be employed at any 
one time for the same measure of milk, varies very much 
according to the quality of the milk and the temperature of 
the atmosphere : thick, rich milk, which has not been skim- 
med, requires more than that which is thin, or from which 
the cream has been removed. In winter it is often neces- 
sary to warm milk slightly to make it curdle. 

As soon as the milk curdles it is allowed to remain un- 
disturbed in a cool place, in order that the curd may ac- 
quire some degree of firmness, and that all the particles may 
become united in one mass, and likewise to allow all the 
whey to drain off : it is then dipped up with a skimmer 
and put into a vat or bucket of osier, through which the 
whey contained in the curd can escape freely. As soon 
as the curd has acquired a certain degree of consistency 
in the willow baskets, it is removed into vats of earthen- 
ware having small holes in the bottom ; through these the 
whey still continues to drop, and the curd gradually in- 
creases in density. Curd, from its first formation to the 
period of which we are now speaking, forms an article of 
diet equally healthy and agreeable, and furnishes a great 

[* In this country the term is applied to the dried and salted stom- 
ach of the calf, a piece of which is employed to produce the coagula- 
tion required. — Tr.] 



210 CIIVMISrUY APPLIED TO AGRICULTURE. 

resource (or variety in the food oi' tlie iiihabitarity of the 
country. But as tliese preparations cannot be preserved for 
any lenijth of time, it is necessary to find some means of 
keeping them free from alteration, or so to moderate and 
govern decomposition, that the food furnislied by tlie case- 
ous matter may be varied, and the power of keej)ing it pro- 
longed : tliis object is obtained in the fabrication of cheese. 

The existence of whey in curd hastens most fwwerfully 
the action of putrid decomposition ; and, in order to pre- 
vent or retard tliis cliange, it is necessary that the whey 
be forced out by mechanical power. Those cheeses which 
are the best dried, may be preserved the longest time ; in 
order to hasten the drying, the curd is carefully kneaded, 
and in some cases the cheese is exposed to lieat or to a 
strong pressure. 

The period during which cheeses can be kept may be 
prolonged, by im])regnating them well with salt ; tliis is 
done in the followinir manner : when the curd has ac- 
quired the requisite degree of consistency, the surface of 
it is furrowed and covered with pounded salt ; the next 
day the cheese is turned, and tlie s;nne operation perform- 
ed upon the other side of it. This salting is repeated tili 
every part of the cheese is well seasoned, it is then placed 
upon a bed of straw, and turned from time to time. The 
straw upon which cheeses are placed, must be frequently 
changed, and the planks washed, and in every part of a 
dairy the greatest cleanliness and neatness should be ob- 
served. 

The surface of a new cheese gradually loses its white 
appearance under the above treatment : the size is diminished, 
and there is formed an external crust harder than the middle, 
and having a sharper and less agreeai)le taste. 

When the caseous matter is precipitated from milk re- 
taining its cream, the cheeses formed from it fire not so 
dry as those which consist entirely of the caseous part; 
their taste is mild and their substance more mellow and 
unctuous. 

Indrpendently of the modifications which cheese is sus- 
ceptible of, from the addition or suppression of cream, the 
mixture of ditTiirent kinds of milk varies it greatly. I for- 
merly remarked that the milk of the sheep and goat was 
softer and more viscous than that of the cow ; this renders 
the cheese made from it mellow, besides its possessing a 
very agreeable flavor. The mo.st celebrated cheeses are 



CASEOUS MATTER. 217 

made from a mixture of cows' milk with the milk of sheep 
or goats. 

I will here give a hasty sketch of the most usual pro- 
cesses by which cheese is made. 

When the curd has been deprived of its whey, except- 
ing what may ooze from it in the vats or upon the straw, it 
undergoes various degrees of decomposition, which at differ- 
ent periods furnish several kinds of food. 

A new or white cheese gradually shrinks, and its surface 
becomes covered with a crust or rind, whilst the interior 
preserves more of its softness : at the end of some time fer- 
mentation takes place, when it exhales an odor which be- 
comes more and more sharp ; a similar change likewise 
takes place in the taste : this stage of decomposition is the 
most favorable for disposing of white cheese. 

When cows' milk that has been skimmed is used for 
cheese, the article produced from it is always dry ; but if 
the curd be formed from milk retaining the cream, the curd 
contains, in addition to the caseous matter, all the princi- 
ples of the cream ; and, when treated in the usual manner, 
a white cheese is obtained from it which is not slow in 
changing its consistence : the interior of such a cheese 
softens and takes the form and nearly all the character of 
cream. Cheese in this state is delicious to the palate ; but 
it soon undergoes a putrid decomposition which changes its 
quality. 

There is a very delicate and much sought for prepara- 
tion, which is improperly called cheese ; this is made by 
churning fresh cream till it has acquired a degree of con- 
sistency, without the butter's being separated from it. 

All kinds of cheese cannot be kept good a long time ; 
but if the curd be strongly pressed so as to extract all the 
whey, and afterwards carefully salted, cheeses may be 
made of it which can be preserved a considerable length 
of time. To effect this, the curd is divided with a wooden 
knife, kneaded, and squeezed with the hands ; and when 
all parts of it have been well worked, it is put to drain. 
As soon as the whey has ceased to drop from it, it is again 
kneaded and submitted to a considerable pressure, by 
which all the liquid particles which can be extracted from 
it, are forced out. 

When the curd has by these operations been brought to 
a due degree of dryness, it is salted : this is done by again 
carefully kneading the curd and afterwards breaking it 
19 



218 CIIYMISTRY APPLIED TO AtilUCULTURE. 

into pieces, into each of uhicli tlie salt is worked by the 
hand ; a mould or form is then filled with the curd ; this 
is covered over with a clotli, uj)on which is placed a weight 
to press the cheese ; by this process tjje salt is made to 
penetrate the whole mass, and the last remaining portions 
of whey are forced out. 

The whey wiiich is disengaged by this last operation is 
very salt, and is usually preserved to moisten cheeses with, 
when by their progress of decomposition they have become 
too dry. 

The curd remains under the press several days, and is 
turned from time to time, that the salt may become incor- 
porated with the mass, and that the whey may be perfectly 
separated from it. 

When the cheese is taken from the press it is placed in 
a situation where the temperature is cool and equal, and 
where it will not be exposed to light or insects, and there 
it undergoes the other processes, by which the making of 
a cheese is completed. These processes vary much in 
different places : in some a cheese is turned every day, 
and its surface, as soon as it becomes dry, is moistened with 
salted whey : if a cheese becomes mouldy, the rind is for- 
cibly scraped with a wooden knife ; in other places the 
rind is scraped and taken olT every five or six days, and 
by this means the part that is most advanced in decompo- 
sition, is removed and sold at a low price to the people. 
As S(X)n as this crust is taken o\Y, the new surface is rubbed 
with salt, which is forced into it with the hand ; the cheese 
is then carried into the cellar : the operation is repeated till 
the cheese is disposed of. 

If, in drying the curd, the action of fire is added to com- 
pression, a firmer, harder cheese, and one of very ditferent 
qualities, is obtained : a cheese prepared in this way can be 
kej)t a longer time than others. 

In the manufacture of this kind of cheese, the milk is 
placed in a boiler over a moderate fire, and the necessary 
quantity of rennet is stirred carefully into it: as soon as 
tiie rennet begins to atfect the milk, it is removed from the 
fire, wlien the curd very soon ac(|uires some degree of so- 
lidity : all the wiiey which can in this state be extracted 
from it, is removed, and the boiler again placed u|)on the 
fire ; the curd is constantly stirred either by the hand or 
with a slip of wood : this operation is continued, till the 
clots which swim in the \vln^y, which is expressed from 



CASEOUS MATTER. 219 

them, have acquired so much firmness, as to resist the 
pressure of the finger, and present a yellow appearance : 
the boiler is now taken fi-om the fire, and the stirring and 
squeezing continued, till the curd is coo', when it is put 
into a mould and submitted to a strong pressure to extract 
all the remaining serum. 

Afi;er these first operations are completed, the curd is 
again kneaded, in order to give it the different forms un- 
der which this kind of cheese is known in commerce. 
The cheeses when formed, are rubbed over with salt ; this 
is repeated every day, and the cheeses are at the same 
time turned ; the salting is completed when the surfaces 
exhibit a superabundance of moisture, as this announces 
the cheeses to be saturated with salt. The cheeses are 
then put into a cool place, where they will be safe from 
insects. 

In general, cheeses made in this way are hard and dry, and 
may be kept a long time : the nature of the caseous mat- 
ter of cow's milk, from which they are prepared, contrib- 
utes not a little to these qualities. 

There is no food made use of by man which presents so 
great a variety as does cheese ; this arises from some cir- 
cumstances of which we can ascertain the causes. 

The milk which is furnished by animals of different 
kinds, is not of the same quality, and consequently the 
butter and caseous matter obtained from it are very dis- 
similar, and the cheese made from sheeps' or goats' milk 
is much more mellow and agreeable than that from cows' 
milk. 

The milk of animals of the same kind varies very much 
with the health, the food, season of the year, length of 
time from bringing forth young, &-c. ; all these circum- 
stances modify the quality of this secretion indefinitely. 

The mixture of milk obtained at different times, during 
a space of several days, the quality and proportion of the 
rennet employed, the temperature of the weather, and the 
calm or stormy state of the atmosphere, the cleanliness of 
the dairy, and of the utensils employed, the degree of care 
with which the curd is freed from whey, the choice of a 
proper kind of salt for seasoning, the course which is pur- 
sued in governing the fermentation, and the size of the 
cheese upon which all these circumstances operate, com- 
bine to influence the quality of the product ; and however 
much care may be taken in the various parts of the process 



220 CHYMISTRY APPLIED TO AGRICULTURE. 

of cheese-makiiig, it is very diiliciilt always to obtain the 
same results : it is for this reason that we seldom have two 
cheeses precisely alike in all respects. 

The custom which is practised in some countries, of 
skimming the milk before forming the curd, gives to the 
product a pocidiar character; such cheeses are dry and very 
suitable for keeping ; they may be made of very great size. 

By mixing the milk of the goat or sheep, with that of 
the cow, cheeses may be made very superior to those ob- 
tained from cows' milk alone : it is from this mixture that 
the two best kinds of French cheese, the Ro<iuefort and 
the Sassenage, are made : if the first of these is superior 
to the last, it is, I think, owing to the cellars in which it 
is prepared : these cellars are backed by a rock wliich 
presents numerous chinks and openings, by which there 
constantly escapes a rapid current of air, which keeps the 
temperature but 4^ or 5° Fahrenheit above freezing ; * the 
fermentation, therefore, is very slow, and may be regulated 
at pleasure. 

Cheeses made entirely of goats' milk are more delicate 
than those made partly of cows' milk, but they caiuiot 
easily be kept for any length of time ; they should there- 
fore be made small, and be eaten as soon as they have at- 
tained thea' perfection. 

Much cheese is made in France, but, with the exception 
of five or six places, but little care is given to this article, 
and the consumption of it is confined to the vicinity in 
which it is fabricated. None of our cheeses are capable 
of being ke{)t any great length of time. 

The importation of foreign cheese is very considerable : 
it is desirable that extensive establishments should be formed, 
where the })roduct from the neighboring dairy farms should 
be brought to undergo the necessary manipulations. 

The maiuifactories of Ro<juefort are supplied in this 
manner with new cheeses bought upon the mountains of 
Larzac. 

The successful attempts which have been made in many 
parts of France, to imitate the cheeses of Holland, Swit- 
zerland, and Fngland, leave no doubt in regard to the 
possibility of introducing this valuable branch of rural in- 
dustry among us. 

• In tho rnontli of July, 17K4, my lli.TiiinuuMcr indiratrd 22 (72° 
Fahr.) in the rxlt'rii.il air ; wiu-n carried into these cellars, it sunk to 
2° (lk)° Falir.), and there remained. 



Agricultural and manufacturing nations. 221 



CHAPTER XII. 

comparison between an agricultural and a manufac- 
turing nation. 

No nation in Europe can be called purely agricultural 
or purely manufacturing ', in all, these characters are more 
or less united. 

But when a nation has formed within itself centres of 
manufacturing industry, the products of which are every- 
where diffused, and when the existence of a large portion 
of its inhabitants essentially depends upon the prosperity 
of its manufacturing establishments, it is justly styled a 
mamifactiiring nation ; whilst the nation which exports a 
large proportion of the products of its soil, and has only 
a few manufactures to supply its most urgent local wants, 
is an agricultural nation. 

Several causes conspire in establishing this distinction. 

A nation which possesses an extensive and fertile soil, 
capable of furnishing occupation to its whole population, 
cannot but be agricultural ; but if its population exceed 
the demands of agriculture, there must necessarily be 
either an emigration of a part of it to other countries, as 
has been frequently observed in the north, or a formation 
of manufacturing establishments to provide them with 
employment. 

Whenever, by the revolutions which have so frequently 
taken place in Europe, a part of the population has been 
forced to migrate into desert countries, of an almost barren 
soil, these colonies have in the first place drawn from the 
soil, by labor, all that it was able to furnish, and manufac- 
turing industry has then become a powerful auxiliary to 
agriculture, in ensuring them a subsistence. The popula- 
tion of mountainous countries everywhere affords exam- 
ples in support of these principles. 

We shall even observe that in those mountainous coun- 
tries, where the frugality of the inhabitants makes labor 
cheap, manufacturing industry has maintained itself and 
prospered, until machinery has superseded manual labor, 
and made it an insufficient auxiliary in the execution of 
products. 

Manufactures have then established themselves wherever 
science and the mechanic arts have made the greatest pro- 
19* 



222 CHYMISTRY APPLIED TO AGRICULTURE. 

gress, and France and England have divided this branch 
of indnslry between them. 

I'^'rance was already in jKJssesdion, almost without a rival, 
of maniitacture.s of silks, lawns, cambrics, laces, fine cloths, 
nnd several other articles essentially connected with its 
acriculture ; but Eiiiiland, toward the middle of the last 
century, opened a branch of industry in the cultivation of 
which she has enjoyed a high superiority till the present 
day, — that of the spinning and weaving of cotton; and, 
since that period, she has carried to a remarkable degree 
of j)orf('ction all other kinds of manufactures. 

France has constantly shown herself superior in the ap- 
plication of chymistry to the arts ; England in the con- 
struction and employment of machinery. 

The application of the sciences to manufacturing opera- 
tions has rendered labor more regular, more prompt, more 
economical ; the fabrication of products has been no longer 
limited, and their consumption has increased, in conse- 
quence of their superior quality and low price. 

But has this great revolution, effected in manufacturing 
industry, been advantageous to the human race ? It has 
unquestionably been so to the undertaker, and to the con- 
sumer ; but has it also been so to agriculture ? 

Formerly, almost all the manufactured articles necessary 
to the inhabitants of the country, were made in every coun- 
try household, and whatever was not needed for domestic 
use, was advantageously sold ; to this labor were devoted 
the long winter evenings, and all the time not required for 
the cultivation of the soil. The low price to which the 
use of machinery has reduced these articles no longer 
permits the farmer to sustain a competition in price, and he 
finds himself deprived of a resource which was of itself 
sufficient to pay his taxes : thus agriculture is a sufferer. 

These large manuficturing centres have attracted the 
inhabitants of the country by the offer of higher wages ; but 
hardly has he entered the establishment, when a total 
change; takes place in him ; he is no longer the frugal peas- 
ant ; in changing labor, diet, and society, he gradually con- 
tracts new habits ; his health is affected, and the human 
race is insensibly deteriorated. Should a stagnation of com- 
merce take place, he is thrown out of emj)loyment, and 
has then no resource but in public compassion. 

These inconveniences are carried to excess in England, 
where the vicissitudes of commerce often peril the exist- 
ence of half the population, and cause disorder in society. 



Agricultural and manufacturing nations. 223 

More happy than England, France cannot be tormented 
by these fears. In a population of from thirty to thirty- 
two millions, the proportion of those possessing no prop- 
erty, is hardly one sixth, and the resources which agricul- 
ture presents are immense. France possesses but two 
great manufacturing centres, Lyons and Rouen ; and when 
the operatives there are out of employment, they disperse 
themselves in the country, where they find occupation. 

Manufacturing and commercial crises are less numerous 
in France than in England, and there are two principal 
reasons of this difference : the first is, that manufacturing 
is carried on to a much greater extent in England than in 
France ; the second is, that the principal markets for the 
products of English labor are abroad, while France 
possesses thirty-two millions cf consumers at home. 

This last advantage in favor of France is immense, be- 
cause nothing can deprive her of it, and because it could 
only be compensated for by the opening of numerous mar- 
kets abroad. In England, agriculture holds a second place ; 
in France, it takes the precedence over manufactures. 

The crises to which agriculture is liable, are less fre- 
quent than those of manufactures, and are not attended 
with the same consequences ; periods of scarcity are never 
so terrible in the country as in cities ; the farmer always 
husbands resources for these calamitous times, and his sub- 
sistence is never made uncertain. 

The labors of agriculture maintain a frugal, healthy, and 
hardy population ; those of manufactories often alter the 
most robust health, and dissoluteness of all kinds is almost 
always an appendage of the manufacturing laborer. 

There is, then, no doubt, that, in many respects, agricul- 
tural is preferable to manufacturing life. 

But, on the other hand, the fortunes made in agriculture 
are slowly and laboriously acquired : such a competition 
in price exists as to the products of the soil, that the profits 
of the proprietor are necessarily very limited ; and although 
agriculture offers an honorable and certain subsistence, and 
one presenting fewer chances of a reverse, yet the greater 
number rush to manufactures, as promising more rapid 
gains. 

Governments, however, almost universally favor manu- 
factures rather than agriculture. This predilection would 
seem to be suggested to them by the example of England, 
who, by means of her manufactures, has reached, in a short 
time, the highest degree of prosperity. 



2*24 CHYMISTRY APPLIED TO AtJUICLLTLRC. 

Agriculture lias yet this advanta^^o ovfr manufacture*, 
that almost all its products are of the first necessity, and 
that the chanjTes of taste, and the caprices of fashion, have 
not the same influence upon it, as upon the products of 
mainifacturinsT industry : a nation rich in its soil does not 
<'xperience those lluctuations to which a manufacturing 
nation is exj)Osed by the mere j)rogress of foreign manu- 
factures. 

In all these respects, the prosperity of France rests 
upon solid bases ; its soil is adapted to all kinds of cul- 
ture, and possesses several pectdiar to itself; the excel- 
lence and variety of its wines, in particular, find consum- 
ers everywhere, and this branch of cultivation alone pro- 
duces at the j)resent day more than a thousand millions. 

We are not, then, to be surprised if France have always 
risen, as by a miracle, from every crisis which she has ex 
perienced, and may conclude, that if she had been wisely 
governed, she would long since have stood first among 
nations. 



CHAPTER XIII. 

OF LARGE AND SMALL ESTATES. 

The question as to large and small estates has for some 
years occupied all minds in France. Some would unite 
all property in the hands of a few families; others are 
willing to leave it to time and private interest to effect a 
suitable division, and one advantageous to the nation and 
the government.* 

Large landed estates spring from the first institutions of 
monarchy ; privileges, grants, and the division of inhab- 
itants into classes, centre all property in the hands of a 
few ; the rest of the jX)pulation, condemned to servitude, is 
attached to the soil. 

Gradually the serfs are freed ; property is divided ; but 
the new j)r(ij)riotors have been able to arcpiire and to 
pos.sess only on burdensome conditions; their lands have 



* Sec the excellent Memoir of the Vicomte de Morel Vind6 on this 
subject. 



LARGE AND SMALL ESTATES. 225 

been loaded with rents and imposts from which the first 
possessors were exempt, and thus two kinds of property are 
established. 

While this state of things has continued, agriculture 
has made no progress ; one class was too rich to perceive 
the necessity of improving their estates, the other was too 
poor to attempt it. 

When the power of acquiring property has been given to 
all, and particularly when the law has equally protected 
all proprietors, and abolished all privileges attached to the 
soil, or to individuals, the result has been a division of 
property, and an advance in agriculture. 

The revolution has had two results advantageous to 
land-owners; the first, that of effacing the last traces of 
inequality in property; the second, that of offering to the 
agriculturist an enormous quantity of lands, which he 
could purchase at a low price. 

The natural consequence of this state of things has 
been to increase the number of landed proprietors, and 
the respectability of the farmer. 

Is the division of the soil into small estates an advan- 
tage or an evil ? That is the question which we are to 
examine. 

Large estates have the advantage of affording scope for 
all the developements of agricultural industry. That 
which forms the basis of subsistence, and a large propor- 
tion of the raw material of manufactures, is here united 
in one grand scene of operation. The productions of a 
large domain not only suffice for the subsistence and sup- 
port of the proprietor and his agents, but the surplus sup- 
plies the wants of all, and fills the public markets. 

Add to this, that large proprietors are more enlightened 
than small ones, and, especially, better enabled, by their 
more ample fortunes, to attempt improvements. 

There is, then, no doubt that large proprietors are de- 
sirable in France ; but are we therefore to be alarmed at 
the increase of small farms ? I think not. 

If, as I have already said, large estates have been the 
necessary result of our ancient institutions, the division 
of landed property is the natural effect of those by which 
we are at present governed. The suppression of the right 
of primogeniture, and of all the burdens which weighed 
unequally upon different classes of proprietors, and the 
prosperity which has prevailed among the inhabitants of 



226 CHYMISTKV AIILIKt) TO AGRICULTURE. 

the country, have necessarily increfised the number of 
land-owners; but will this increase be unlimited? No; 
it will stop when the advantage of extensive acrricultural 
operations is more fully realized, and when the ])roduce 
of the soil can no longer liberally pay the labor of which it 
is the object. 

To elucidate this (juestion, let us see what has taken 
place hitherto. 

In districts devoted to the greater crops, the division of 
land has had no sensible etTect ; everywhere we find the 
same extent of agricultural improvement, and the supplies 
of cattle, corn, fodder, and wood for the market have 
suffered in no way. 

In a very large number of communities, of which al- 
most the whole territory belonged either to the nobles or 
to the clergy, those of the inhabitants who were already 
proprietors have bought as much as suited their con- 
venience, and those who were not proprietors have be- 
come so. 

But it is particularly in districts devoted to the lesser 
crops, that the division of property takes place; there, 
almost all the labor is manual. Tlie culture of the vine, 
and that of the different kinds of pulse, require })articular 
care and intelligent superintendence. To this the small 
proprietor consecrates all his time ; he labors at the best 
times and the most favorable seasons ; he employs the rest 
of his time in laboring for the public. 

Let us now observe the results of the division of the 
soil into small estates. 

These results may be considered with reference to three 
points : the interest of agriculture, the welfare of the state, 
and public morality. 

I. The intrrrst of agriculture. 

When a large proprietor directs his information and 
his wealth to agricultural improvements, this is without 
doubt advantageous to agriculture ; but these examples 
are rare. The cultivation of a large domain is usuallv 
entrusted to farmers, who follow step by step the received 
methods, and do not venture to adoj)t useful changes, be- 
cause the sliorfiicss of their hsiscs docs not jx-rmit them 
to hope to rrap the benefits of them. It is raro, too, that 
in a very extensive tillage, there is enough of hands, of 
maiuire, and of working cattle, to carrv cnhivati(tu to its 
perfection. 



LARGE AND SMALL ESTATES. 227 

It cannot be denied that the first interest of agriculture 
is to produce the greatest possible amount upon a limited 
extent of soil, and to furnish produce at the lowest price 
to the consumer : now, in this case, all the advantage is 
in favor of the small proprietor ; he cultivates the soil 
himself, and brings to his labor all the interest of a pro- 
prietor ; he labors only at the most favorable times, and 
gives his unoccupied time, for wages, to the work of 
others: the large proprietor is not at liberty to be thus 
guided by his convenience ; he is hurried along and com- 
manded by time and labor. 

The small proprietor leaves no part of his ground un- 
occupied ; he cultivates steep banks with pulse ; plants 
potatoes in any vacant space in his vineyard : the large 
proprietor neglects all these details. 

2. The loelfare of the state. 

It is generally admitted, that the large domains, which 
have been divided in consequence of the revolution, pro- 
duce much more than they did ; that uncultivated lands, 
especially in the south, are now covered with noble vine- 
yards ; that prosperity has prevailed in the country from the 
increase of the number of proprietors. 

These undeniable facts have produced important ad- 
vantages ; the increase of produce has furnished means for 
the subsistence of a more numerous population. Wealth, 
introduced among the inhabitants of the country, has 
enabled them to maintain their children, and give them a 
better education ; the consumption of produce of all kinds 
has increased, and agriculture and manufactures have found 
larger markets for their products. 

So long as twelve years ago (I write in 1826), the 
amount of taxable quotas in the land-tax was ten millions 
four hundred and fourteen thousand one hundred and 
twenty-one, according to the last lists furnished by the 
Duke de Gaeta. The taxable quotas under 500 francs 
amounted to nine millions nine hundred and fifteen 
thousand. Since that time the number of quotas has in- 
creased, and particularly the smaller ones. And never has 
the land-tax been more regularly paid. 

Another advantage resulting to the state fi-om the di- 
vision of property, has been that of rendering changes 
more frequent, a natural result of the increased number 
of proprietors : these changes, as they become more nu- 
merous, bring much more money into the treasury. 



^2r2S CHYMISTRY APPLIED TO AGRICULTURE. 

According to the very exact verification made for five 
years by the department of indirect taxation, there were 
produced on an averajrc, at the commencement of tlie cen- 
tury, tliirty-five millions and six hundred thousand hecto 
litres* of wine : this amount has remarkably increased since 
that time, not only because the vine has continued to be 
planted, but because the culture of it lias been improved ; 
the case is almost the same as to all the produce of the 
Foil. It cannot be denied that this increase of production is 
the result of the division of the soil into small farms. I 
have been for some time the proprietor of a pretty extensive 
vineyard, which I carefully cultivate, and I have constantly 
observed, that the sniall proprietors who worked for me 
raised at least double from an equal extent of land belong- 
ing to them ; my produce, in truth, was of a little superior 
quality ; but, at the market price, the quantity more than 
compensated for this difference in quality. 

3. Publir mnrnliti/. 

But it is particularly as it respects public morals that the 
increase of the nund)er of small proprietors is advantageous. 
To be convinced of this, we need only compare the condi- 
tion of the man posse.-^sing no property, with that of the pos- 
sessor of proj)erty, however limited in extent. 

The laborer without property is retained only by habit 
in the place of his birth ; his two hands are his only prop- 
erty, and he places them at the disposal of him who pays 
best ; he is entirely dependent upon the work he finds 
about him, and when employment fails, he changes with- 
out regret his place of abode, to seek it elsewhere. The 
institutions of his country are indifferent to him, because 
he takes no part in i)ublic affairs; he feels no interest in 
the preservation of order, because a state of disorder pre- 
sents to him more favorable opportunities. Almost always 
discontented with his situation, he becomes restless, jeal- 
ous, miserable : he accuses God and man, and .seeks every 
opportunity which offers of rendering it better. Troubles, 
insurrections, robberies, assassinations are frecjuent wher- 
ever there are many laborers without property and few 
proprietors ; and governments are forced to establish 
enormous pnor-rnfrs, as in England, or to supjily the poor 
with food at the gates of convents or chateaux, as in 
Spain. 

* See note, page 131. 



LARGE AND SMALL ESTATES. 229 

The subsistence of the laborer without property is never 
certain; the frequent diminution or suspension of labor in 
manufacturing establishments reduces him to misery, and 
promotes the developement of all the vices which result 
from it ; the labors of the country vary with times and 
seasons, and do not offer constant employment to one not 
attached to the farm. His lot is then always variable and 
precarious. 

The man without property who is single, commonly leads 
a dissolute and intemperate life ; he who would have a family 
commonly becomes more unhappy ; he cannot give his chil- 
dren a suitable education, and they soon contract all the vices 
of a depraved society. 

The condition of the small proprietor is very different 
from this ; he is rooted to the soil, and thence derives all the 
advantages of his situation. He works on his own land in 
his leisure moments, and devotes the rest of his time to 
earnincr wao;es on the estates of others. This double source 
of profit abundantly secures his existence and that of his 
family. His children and his wife cooperate in the culture 
of his little farm ; idleness is banished from their household, 
and good morals, which are always the result of a laborious 
life, prevail there. 

The small proprietor is interested in the maintenance of 
public order, because he would be a loser by trouble and 
disorder ; he loves the institutions and the government which 
protect his property ; he regards the welfare of others, be- 
cause he would have others reorard his own. His interest, 
his affections, his fears, his hopes, are concentrated and 
repose in that little spot of earth whose safety and 
prosperity are his only wish. He has in truth a country, 
whilst the other is a true cosmopolite, a stranger to all social 
interest. 

Some appear to be alarmed at the increase of population 
attendant upon small proprietorship ; but this increase of 
population is a certain sign of an increase of the means of 
subsistence and of the wealth of the inhabitants, whilst the 
diminution of population announces public misery. 

In proportion as the population of the country increases, 
manual labor becomes more abundant, and produce increases 
in quantity and is reduced in price. 

Thus, stripping the question of all that is connected 
with certain political considerations, the division of land- 
20 



230 CIIVMISTRY AI'PLIKD TO AGRICULTURE. 

rd projH'rty is an advantage to agriculturn, to the state, to 
public morals. 

Men who take their opinion only from the past, would 
bring back property to its Ibrmer state; but times are not 
the same, and a return to the ancient order of things is 
inij><)ssible. The division of property will continue to take 
place, so long as the small proprietor shall obtain more 
l)r(>duce from a given extent of land than the large one, 
and so lonu as larorc owners shall divide their lands into 
small lots, to obtain a more advantaoreous sale of them ; 
it is evident that a dilferent result could be obtained only 
by reducing the destitute laborer to a degree of misery 
which would not jxjrmit him to economize with a view to 
ac(juiring property, or by prohibiting sales of land in small 
j)ortions ; now, the first of these means is contrary to jus- 
tice and good morals, and the second to the rights of prop- 
erty. 

When, in the session of 182."), the government projxjsed 
to reestablish the right of primogeniture, it had neither 
paid reijnrd to the changes which had taken place since 
the revolution, nor to the respective rights of the different 
members of the same family. Formerly, almost all the 
large estates belonged to the most ancient families in the 
kingdom ; they passed, undivided, into the hands of the 
eldest son, because the army, the clergy, or the order of 
Malta aflfordcul rich endowments Hir younger sons, and con- 
vents oifered great resources for daughters ; but, at the 
present day, what would become of younger sons if the 
right of j)rimogoniture were reestablished ? Deprived of 
the expedients olFered by the old state of things, incapable 
of laboring n|x>n the soil, they would live at the mercy of 
the head of their family. It is then ]>articularly to old 
families, which, notwithstanding, it is meant to benefit, 
that the reestablishmeiit of the right of primogeniture 
would be fatal. 

Let us but leave it to time and to private interest, and the 
division of property will not pass the bounds prescribed to it 
by these supreme reiiulators of all things. 

The division of estates will contimu' to take place, 1. in 
the vicinity of cities, where, from the constant attention 
bestowe<l on the soil, from the abundance of manure, the 
facility of transjM)rtation, the proximity of the market, and 
the certainty of a safe and advantageous sale, immense 
crops of v(>2etables and fruits of all kinds and of every 



LARGE AND SMALL ESTATES. 23 i 

season may be obtained by manual labor ; 2. in vine coun- 
tries, where the cultivation requires constant labor, and 
where the production is always proportional to the care 
bestowed upon the land ; 3. in uneven lands, like valleys, 
mountains, &.c. where cultivation is confined within narrow 
limits, and where the lands capable of it are separated by a 
barren soil. 

In all these cases, the plough and working-cattle can- 
not be employed in labor ; every thing is done by manual 
labor, and at most, the owner of each estate possesses a 
few cows and goats, and sometimes a few sheep, to secure 
subsistence, and increase the comfort of his household. 
We often find a numerous population assembled in those 
wild places where the soil seems to refuse any cultiva- 
tion, and where the inhabitant, temperate and hardy, ob- 
tains, by industrious labor, crops which satisfy his wants 
and supply the neighboring markets. Those numerous 
countries, which are not capable of high cultivation, would 
be deserted without the assistance of the small proprietor ; 
and it may be said, to his credit, that he creates produce 
in places which nature had devoted to the most complete 
sterility. 

We nowhere see small proprietorships existing in places 
favorable to hio-h cultivation. The vast domains of Beauce, 
Brie, Soissonnais, Upper Languedoc, exist undivided, and 
are always the granaries of France ; the rich pasture lands 
of Normandy, Poitou, Anjou, &c. always maintain the 
same number of cattle ; our laro;e forests have remained 
untouched ; population and the means of living have con- 
siderably increased ; our markets are abundantly supplied ; 
wealth has spread through the country ; manufactures have 
made immense progress ; taxes are paid regularly and with- 
out compulsion. 

Let us beware of disturbing, by laws or regulations 
relative to property, this general harmony and public pros- 
perity, which secure the happiness and prosperity of our 
country. 



2i>2 CHYMISTUY APPLIED TO AliRICULTURE, 



CHAPTER XIV. 

THE ENCOURAGEMKNT WIIU'H (H <.ir T TO BE (JIVEN BY THE 
GOVERNMENT TO FRENCH AGRICULTURE. 

Tin: vrry liniittd degree of information which, even to 
the present day, has been diffused in the country, and the 
almost abject part which the cultivator of the soil has been 
made to play, have arrested the i)rogress of agriculture 
there ; faulty methods of cultivation have been retained, and 
France has been far outstripped by other nations in this no- 
ble career of public prosperity. 

Now that our institutions have replaced the most useful 
class of men in the tirst rank in society, it is to be hoped 
that the agriculturist will feel all liis dignity, that he will 
love his condition, and that, by labor and instruction, he will 
create resources hitherto unknown to him. But this useful 
revolution requires the support of government; lands are too 
much divided, the fortunes of {)roprietors are too limited, to 
allow the expectation of seeing great examples and useful 
lessons given without public assistance. 

In France, the most frivolous arts are almost everywhere 
provided, .ii ihe cost of government, with the facilities for 
practical instruction ; and agriculture alone is destitute of 
a public establishment, where the priiicij)les and practice 
of this beautiful science may be taught. The need of 
communicating instruction through the country is so gen- 
erally felt, that we see, in every department, educated ag- 
riculturists associated for the purpose of connnuiiicating 
their observations, of discussing new processes, and of 
proposing the imjirovemcnts of which agriculture is sus- 
('«'i)til)le. 

These associations are useful ; they render important 
services; but they have not the advantage of forming 
young agriculturists, nor of making them accjuainted with 
the true principles of the science. We need, for this ob- 
ject, special instruction and men who shall be exclusively 
devoted to it. 

in iitiglaud, where rural fortunes are divided among 
from twenty-two to twenty-five thousand families, wealthy 
proprietors establish |)rizes, of whirh they make a formal 
distribution every year. They assemble within their do- 
mains, UjK)n a fixed day, a considerable number of agricul- 



DUTIES OF THE GOVERNMENT. 233 

tarists, each one of whom produces for examination and de- 
cision the finest products of his cultivation. These festivals, 
instituted for the promotion of agriculture, excite the most 
active emulation and produce the happiest effects. 

It has been in vain attempted, in France, to imitate Eng- 
land; fortunes are here too limited to enable individuals to 
meet expenses so considerable. Government alone can and 
ouorht to furnish such institutions. 

It would be necessary that at least two experimental 
schools of agricultural instruction should be established in 
France, one in the south, and the other in the north, in order 
to embrace all kinds and varieties of culture which belong 
to our soil and our climate. 

The extent of land devoted to each establishment should 
be about two hundred hectares,^ and the buildings should be 
able to lodge at least one hundred pupils. 

The nature of the soil must be sufficiently varied to ad- 
mit of all the different kinds of culture adapted to the 
climate. 

There would be required in each establishment a director, 
entrusted with the care and management of it, and two pro- 
fessors, one of Chymistry applied to Agriculture, the other 
of Veterinary Medicine. 

The purchase of lands and the cost of the establishment 
might be estimated at from a million to twelve hundred 
thousand francs; but the money paid for board and the 
profits of cultivation would at least cover all the annual 
expenses. 

It would be useful to connect with each establishment a 
workshop, for the manufacture of all implements of husband- 
ry, perfected or newly invented, or employed in rural opera- 
tions. The profits of the workshop would form a consider- 
able revenue for the establishment. 

The young people admitted into the establishment as 
boarders should be employed in all agricultural labors ; they 
should be instructed in the responsible management of an 
estate. 

There should annually be a formal distribution of prizes 
to those pupils who have distinguished themselves by 
good conduct, and to those who have made the greatest 
progress. 

A royal ordinance should establish these principles, and 



The hectare is equal to 2 acres, 1 rood, 35.4 perches. 

20* 



234 CnVMISTRY applied to AiiRICULTURE. 

the Minister of the Interior shoukl make the rules necessary 
for securinor their execution in every particular. 

1 liave no doubt that these two estal)lisliments would 
produce, in a few yearn, the best effects upon French ag- 
riculture. Tiic pupils who left these scIkxjIs would ditfuse 
everywhere instruction and good methods of cultivation, 
and the first of arts would no longer depend for preserva- 
tion on a mere routine, which perpetuates errors and pre- 
judices. 

In establishing these two schools, the government will 
liave fulfilled only one part of its duties to agriculture; it 
owes it roads and canals to facilitate the tran.'^ixjrtation of 
couimodities ; it owes it a wise regulation of taxes, so that 
they may never represent a single part only of the benefit 
derived from agricultural operations ; it owes it a kind and 
paternal administration ; it owes it assistance when arci- 
(Idital casualties or diseases hsive ravaged crops and destroyed 
cattle. 

And even in tliis, the government has not yet fulfilled 
all its duties to agriculture, to their fidl extent ; it should 
excite emulation, which, in the arts, works miracles, and 
should reward agriculturists who make important discove- 
ries, and those who improve or extend useful methods of 
cultivation. 

These pecuniary encouragements should not be distributed 
at random, nor badly bestowed, for they would then extin- 
guish cnuilation in j)lace of rousing it. 

A well-selected jury should designate, every year, to the 
authorities, those cultivators of the department who have de- 
served best of agriculture; and the distribution of prizes 
should be made in a public and solemn sitting. 

The object of the examinations of the jury should be to 
determine who are those airriculturists who have introduced 
uj)on their estates animals more valuable and more useful 
than those of the country, and those who have improved the 
native breeds ; 

Those who have established the system of cropping most 
favorable to the soil ; 

Those who have discovered modes of manuring and im- 
|)roviii(r the soil, before unknown or not used ; 

Thos»' who have planted the largest number of tiees; 

Those who have opened to culture lands hitherto barren ; 

Those who have introduced tho cultivation of plants, the 
produce of which is more profitable than that of those usual- 
ly raised ; 



DUTIES OF THE GOVERNMENT. 235 

Those who have invented or nnproved agricultural imple- 
ments ; 

In a word, all those who should have rendered services in 
any department of agriculture, would be entitled to these 
rewards. 

I believe that prizes to the amount of ten or twelve thou- 
sand francs, annually distributed in each of the principal de- 
partments, would be sufficient to excite a happy emulation 
among agriculturists. 

The government should also reserve to itself some places 
in the two practical schools of agriculture, and there place 
the children of the most distinguished cultivators, to be 
maintained at its expense. 

But it is not enough to create agricultural products ; chan- 
nels must be opened to them, and a market secured ; and 
thus the government has other duties to fulfil. Whatever 
facilitates transportation will become of general utility, by 
increasing the consumption of commodities, and lowering 
their price ; the first object of attention is then the means of 
attaininor this end. 

To arrive at a conclusion respecting these means, we must 
first state the present condition of things. 

There are some roads, which may be called parish roads, 
which merely form a communication between the estates of 
one parish ; these consequently are merely roads for farming 
operations. 

There are others, which form a communication t)etween 
adjacent parishes, and which may be called district roads. 

There are also others, which connect together all the 
towns of a department, which may be called dcpartraental 
roads. 

And finally, the great roads, which form communications 
between all the departments. 

The care of maintaining parish or farm roads is entrusted 
to the local authorities, and one needs only a hasty journey 
through France, to be convinced of the neglect and care- 
lessness with which these communications are treated. 
Transportation on these roads is difficult and tedious ; twice 
the number of animals are employed upon them which 
would be necessary if the roads were kept in a proper state, 
and the price of commodities is increased by the difficulty 
of transportation ; all this is detrimental to the proprietor, 
who indeed admits it, but no one is willing, at his own ex- 
pense, to make repairs by which all would be benefited, and 
the evil continues. 



236 CIIYMISTRY APPLIED TO AGRICULTURE. 

To obviato these inconveniences, it would be necessary 
that eacli iiumicipal council sliould jircpare a statnnent of 
all the uc'iirhborini; roads, anil of all the iniproveuieiits wliich 
they recjuire ; this statement should be submitted to the sub- 
j)refect, who should s«mi(1 it to the; mayor, with his o])inion 
thereon ; the expense should be assessed ujxjn the proprie- 
tors at so nmch per franc of their land-tax in the parish. 

If it is dillicult to induce the proprietors of a sintjle par- 
ish to contribute to the maintenance of their farmin<T road.-, 
it is iimch more so to bring two parishes to unite in the 
repairs of their district roads. The rivalry often exi.sting 
between them, the (greater or less interest which thev have 
in the use of the road, are obstacles in the way of the com- 
mon good. 

It is here that the authorities should interpose. Already, 
almost everywhere, the district roads have been usurped by 
tlie neighboring proprietors, and it is not by means of the 
local authorities that a redress of these grievances can be 
hoj)ed for ; for the members of the municipal councils and 
of the municipalities, themselves the largest proprietors in 
the parishes, are the first usurpers. 

I would have attached to every department a superintend- 
ent of bridges and highways, whose duties should be confin- 
ed to whatever relates to the district roads. A stranger to 
all local interests, he should prepare a plan of the district 
roads, should reduce within the limits of their own estates 
those who have encroached upon the public road, should 
prescribe the necessary repairs, point out the nature of the 
materials to be employed, and direct all the labor ; and all 
his plans should be put in execution, after having been sub- 
mitted to the engineers of the arrondissement, and aj)proved 
by the chief engineer. 

The parishes interested should pay the expenses by an 
assessment u|X)n their revenue, their additional centimes, 
and partly by a payment in kind, with the approbation of 
the prefect. 

The de]>artmental roads, which f)rm cojnnuniications be- 
tween the principal towns of a dej)artm('nt, are of more gen- 
eral use and interest than those of which we have just been 
speaking; these should be maintained at the expenst^ of the 
department itself; and the general council, t(j which funds 
are entrusted for this object, should make it one of its prin- 
cipal subjects of deliberation. 

The great roads, which traverse all the departments, 



DUTIES OF THE GOVERNMENT. 237 

tire of general interest, and should be established, superin- 
tended, and maintained by the government itself. 

These four kinds of communication correspond to each 
other, and are bound together by a common interest ; they 
may be regarded as arteries in the social body, which carry 
life to every part. 

When these channels of communication shall be well di- 
rected and carefully maintained, transportation will become 
more easy, more prompt, and cheaper, all which is for the 
advantage of agriculture ; we shall no longer see portions of 
the population enclosed within very narrow limits, and con- 
demned to produce no more than they can Gpnsume, and to 
derive but small advantage from certain natural products, 
such as the wood which crowns the summits and covers the 
sides of almost all our mountains. 

These communications, established through the country, 
will not only tend to facilitate the interchange of commod- 
ities and to increase production, but will have a favorable 
influence upon civilization. By bringing the inhabitants 
nearer to each other, they establish improving social rela- 
tions between them ; mutual assistance is rendered ; mu- 
tual instruction afforded in the art of cultivation ; and 
society, in its turn, profits by all these facilities for social 
union. 

If to these communications by land, rendered as easy and 
as extensive as necessity requires, we add the immense ad- 
vantages of navigation upon rivers and canals, agriculture 
will soon have little to ask of government. 

There are few parts of France where canals cannot be 
made, or the navigation of rivers improved. When the 
grand scheme of navigation, which has been for three years 
provided for by a law, shall be executed, great means of com- 
munication will be opened ; and it only remains to terminate 
this excellent system by branches, to secure to France all 
the benefit of navigation. 

Then the varied productions of France will be conveyed 
to all points ; the price of commodities will everywhere 
diminish, consumption will necessarily increase, and we shall 
not again see one district exposed to the scourge of famine, 
without others being able to supply it, except at a great 
expense. 



238 CHYMISTRY APPLIED TO AGRICULTURE. 

CHAPTER XV. 

ON FERMENTATION. 

The process of dccomjwsition commcncps in all the pro- 
ducts of vegetation, as .s(M)n as they are ripe, or separated 
from the plant. Air, heat, and water, which before this 
concurred in promoting their formation and (growth, be- 
come now the principal agents in the changes whicli they 
undergo. 

The aj)pearances and the new products resulting from the 
decomjMJsition of bodies, vary according to the nature of 
their constituent principles. 

Generally sj)eaking, all vegetable substances decay when 
left to experience spontaneous decomjx)sition ; but when, by 
being exposed to mechanical pressure, those parts of the 
fruits which have been separated are again mixed, there 
arises a new product. The gra])e, for instance, rots upon 
the vine, whilst the juice expressed from it undergoes 
the vinous fennentation. It has for a long time been in 
the power of art to excite, ret.ird, and modify decom|X)sition, 
so as to form new articles of food and drink, for men and 
animals. 

In vegetable products, all the principles are in a state of 
combination and saturation, one with the other : whilst 
the plant lives, its organic energies exert an influence 
over external agents, and preserve in their natural propor- 
tions the elements, which enter into the composition of the 
products. 

As soon as a plant dies, or a fruit becomes ripe, a new 
order of things takes place: tlie difleront parts of the vege- 
table, being no longer influenced by tlie laws of vitality, 
become subject to the power of external agents ; air, wa- 
ter, and heat exercise over \\w\u an almost absolute sway ; 
oxygen, by depriving them of their carbon, destroys the 
projKirtions of their constituent principles; water produces 
the same effect by dissolving certain portions of the sub- 
stance ; and heat, by separating the j>artirles, weakens 
their union, and facilitates the action of the two other 
powers. 

According to the experiments of M. Gay-Lu.ssac, the 
juice of grapes expressed in a vacuum does not ferment ; 
but from the moment that the air is allowed admittance to 



FERMENTATION. 239 

it, fermentation takes place, and, without farther assistance 
from air, goes through all its stages. 

Nearly all the methods made use of at the present time 
for preserving animal and vegetable substances from decom- 
position, are founded upon preserving them from the action 
of air, water, and heat, as I have already shown. 

At the moment when the air, or any other external agent, 
deprives a vegetable of ever so small a portion of one of the 
elements which enter into its composition, the body be- 
comes imperfect, the proportions between the principles are 
no longer what they should be, and decomposition cannot be 
prevented ; there will then be formed new products by the 
union of the elements of the vegetable among themselves, 
or by their combination with the foreign bodies which act 
upon them. 

When a dead body is disorganized by mingling together 
all its principles, decomposition proceeds either with greater 
or less rapidity, because the affinity between the parts being 
awakened, the several agents act more readily upon it. 

Whenever man wishes to appropriate to his own use the 
product of a fermentation, it is necessary for him to inter- 
fere by directing the progress of it. The greatest number 
of fruits contain all the elements necessary for forming the 
vinous fermentation ; but these elements are separate in 
them, and it is therefore necessary to mix and incorpo- 
rate them together by the expression of the fruit, to produce 
this fermentation. The leaves and the woody fibre of plants 
are susceptible of putrid decomposition ; but in order to pro- 
duce it, they must be heaped together and moistened with 
water. 

To produce a speedy fermentation of juices, it is neces- 
sary to collect them in a convenient quantity, and expose 
them to a determined degree of heat : without these pre- 
cautions there will be, to be sure, decomposition, but often 
without any useful result. 

The vinous fermentation is the most important of any, by 
reason of the usefulness of its products; I shall, therefore, 
speak particularly upon it. 

The vinous fermentation takes place only when two prin- 
ciples of very different natures act upon and decompose 
each other : the result of this decomposition is alcohol. 
The first of these principles is sugar ; the second is a sub- 
stance very similar to animal gluten, which is found more or 
less abundantly in the various kinds of grain, and in the 
juice of some fruits. 



240 ClIYMISTRY APTLIKD TO AiiUICULTURE. 

Those fruits froin w liich the juice is expressed to undergo 
the vinous fermentation, contain both these principles, but 
thry exist in tlieru separately : the extrar.tion of the juice by 
jtressure, mixes them intimately, and they then act ujx)n and 
deconijX)se each other. 

In well-ripencd i^rapes, tlie two principles exist in the 
exact pr<)})()rtioiis for j)roducin(( the best results from fer- 
mentatioFi ; but in the crrains which are equally used for the 
fabrication of spirituous li<iuors, the sutrar is separated when 
tlie irrain is made to ircrminate, before beinfj submitted to 
fermentation.* 

Some of the substances which by fermentation yield al- 
cohol, re(juire the addition of some foreign matter, in order 
that fermentation may commence and pass regularly through 
its various stages. The substance used for exciting fer- 
mentation, is called hnvcv, ftrninit, or yiast ; and is al- 
niost always a partially fermented matter containing a large 
]x>rtion of the vegeto-animal princij)le. The scum which 
rises upon the top of licpiids undergoing fermentation, or a 
fermented dougli of wheat, rye, or barley, is used for this 
purpose. 

Leaven, when mixed with any liquid containing sugar, 
continues to ferment, and communicates the action through 
the whole extent of it. 

When the must of grapes has, by boiling and evapora- 
tion, been reduced to the state of an extract, the vegeto- 
animal principle contained in it is disorganized, and it can- 
not be made to ferment without the addition of some foreign 
body. 

Jn order that fermentation may pass regularly through 
its several stages, and furnish a product free from all ten- 
dency to a sj)ontaneous and final (lecomjK)sition, it is ne- 
cessary that the sugar and leaven should exist in the sub- 
stance in suitable proportions : — if the proportion of sugar 
be too great, it will not be entirely decomposed, and the 
fermented licpior will retain a sweet taste: if, on the other 
hand, the quantity of leaven predominate, a part of it will 
remain undecomj)osed in the mass, and the nature of it 

* In the process of germination, oxypen, which is the sole agent, 
combines with the carbon, and causes the developement of sugar in 
the grain. However, the iirinentation of grain which has not first 
germinated, produces gradually the same results when distilled ; aa 
tlie first efiect of fermentation as well as of germination is to throw 
off carbon. 



FERMENTATION. 241 

being changed by fermentation, it will become in time sour 
or putrid, according to the nature of the body upon which 
it acts. 

Generally speaking, the French grapes when ripe contain 
such proportions of sugar and the vegeto-animal principle 
as are well adapted for producing the vinous fermentation ; 
but when the summer is cold or damp, the proportion of 
sugar is less, and the predominance of the mucilage renders 
the liquor weak. In this case, the small quantity of alcohol 
which is developed is not sufficient to preserve the wine 
from spontaneous decomposition, and at the return of heat, 
a new fermentation takes place, the product of which is 
vinegar. This evil may be easily obviated by artificial 
means : it is only necessary to add to the liquor such a quan- 
tity of sugar as would naturally have been found in it, under 
usual circumstances. 

For ascertaining the quantity of sugar which belongs to 
the must of well-ripened grapes, the following hints will be 
sufficient. 

In the south of France, the grapes usually arrive at a state 
of perfect maturity, and if the fermentation be well conduct- 
ed, the wine will keep well ; but in the north, however fa- 
vorable the season may be, the grapes never become perfect- 
ly ripe. I have always observed that the wine of the south, 
which had been well fermented, marked upon the aerometer 
some fractions of a degree below the specific gravity of wa- 
ter, whilst the new wines of the north rarely cause the 
aerometer to descend to the same deo-ree. 

Another important circumstance by which we must be 
guided in ascertaining the quantity of sugar necessary to be 
employed, is the degree of concentration of the must : this 
varies with every vintage, and the aerometer has often indi- 
cated to me a difference of concentration, varying from 2' 
to 4° (= specific gravity of 1.014 to 1.029,) in the must 
procured from the same vineyard, according to the state of 
ripeness which the fruit had acquired ; the heaviest must be- 
ing furnished by the ripest grapes. 

In Touraine, and upon the borders of the Cher and the 
Loire, the weight of the must varies from 8.5° to 11°; 
(z=. specific gravity of 1.063 to 1.083.) I have observed it 
in the south to range between 10° and 16° (= specific 
gravity of 1.075 to 1.125.) Having once ascertained the 
specific gravity of the must obtained from perfectly ripe 
grapes, it is only necessary to bring to the same weight, by 
21 



242 CHYMISTRY APPLIED TO AGRICULTt'RE, 

the addition of ii fiufi'icient quantity of sugar, the must of 
8uch grapes as grow in seasons less favorable to their ma- 
turity. 

lu 1817 the grapes of Touraine did not ripen well, and 
consetjuently the must from my vintage, which in favorable 
years marks 1J° (= specific gravity of 1.083,) stood only at 
9" {=z sp. gr. 1.007.) I rai.-^ed it to 11° (— sp. gr. 1.083,) 
by the addition of sugar, covered the tub with boards and 
W(X)lI('ii cloths, and left it to f(*rnicnt. The wine cleared 
iiHt'ir through the vent of the vat, and had nearly as nmch 
strength as the southern wines, whilst that which had been 
put into a tub without the addition of sugar was as flat and 
tliick as tlie coarse red wine of such vintages usually is. 
The last kind of wine usually sells for fifty francs per butt, 
and I have refused sixty-four for mine, preferring to keep it 
for my own table. 7'he wine to which the sugar had been 
added was as clear as some that had been four years in the 
cask, and was nmch more agreeable to the taste. Twenty 
butts of wine j)repared in this way recjuire one cwt. of sugar. 
The mode is as follows. 

As soon as the gra])es are pressed and the must poured 
into a vat, a jMjrtion of the same li(|uid is put into a boiler and 
set over the fire, where it is sutliciently heated to dissolve 
the sugar : as soon as the solution is completed it is thrown 
into the vat, and the whole well stirred : this operation is re- 
peated till all the (juantity of sugar to be employed is com- 
bined with the liquor. 

Some authors advise, that the nmst itself be boiled till it 
is reduced to one half; but I am not of the opinion that this 
is the best mode of proceeding. Boiling reduces a portion 
of the vegeto-animal principle to a concrete state, and thus 
aflfects the fermentation of the li(|iior : I have always lim- 
ited the degree of temperature to which the must should be 
heated to 35° or 40°.* In the northern parts of France, 
where grapes never rij)en, they may by means of sugar carry 
the concentration of the must one or two degrees farther 
than that of graf)es which grow in the best years, and the 
wine will thus be render'^d far richer and likewise less lia- 
ble to (l»'romjH>sition. 

The following are the advantages to be derived from this 
method. 

[• No Hcnlr is incntioiK^d : if tlio onn roforrcd to ho tho centigrade, 
the oqiiivalcnt niimlMTs upon Faiirenlieit's are 1)5- and 104 '; if R^au- 
mur'a, llOJ^ and V2.i — Tk.J 



FERMENTATION. 243 

1st. When the liquor in the vat is heated by means of the 
solution of sugar, the temperature is raised to 1*2° or 14°,* 
and this causes the fermentation to take place more 
speedily. 

•2d, By covering the vat, the liquor is secured from expe- 
riencing those variations of atmospheric temperature, which 
may either hasten, retard, or suspend fermentation. 

3d. The heat developed in a close vat is more intense than 
that in an open one, and the decomposition of the must is 
consequently more perfect. 

4th. The addition of sugar gives rise to an additional 
quantity of alcohol. 

5th, The head of the liquor is much less apt to become 
sour. 

6th. The wine is more equal and less susceptible of 
change. 

7th. The loss of alcohol by evaporation is less than in un- 
covered vats. 

As next to that of corn the harvest of wine is the most 
important one, inasmuch as it forms our principal article of 
commerce with foreign countries, too much care cannot be 
taken in the manufacture of it.f 

It is customary with most of our proprietors of vine- 
yards to plant upon the same soil vines of different kinds 
of grapes, the fruits of which do not arrive at maturity at 
the same time. This custom is particularly practised in 
those vineyards which produce wines of middling quality ; 
and it has been introduced and continued in them, because 
the different kinds of vines do not flower at the same time, 
but are some of them earlier than others, and some of them 
more sensible to the influence of the changes of the at- 



[* If the centigrade thermometer, the correspondinfif decrees of Fah- 
renheit's are 53.6° and 57.2° ; if Reaumur's 59° and^(3:l2°. — Tr.] 

t The mean value of the products of the vineyards of France from 
1805 to 1809, was about 36,000,000 hectolitres of wine, (= 7,548,285 
pipes, 1 hhd. 27 gals.) According to an examination afterwards made 
by the board for the levying of indirect duties, which claimed some 
right over this liquor, the valuation here mentioned is believed to be 
far short of the truth. 

Vineyards which had then been recently planted, and consequently 
produced but little wine, now afford abundant crops; and as new 
ones are constantly planted, I am convinced that the product of the 
vintage is very considerably augmented. It is I think probable, that 
the harvest of wine equals at this time nearly 50,000,000 hectolitres, 
(— 10,483,737 pipes, 1 hhd. 5 gals.) 



244 rnvMisTRY applied to agriculture. 

mosphcre ; it therefore rarely happens that either one or tlie 
other does not bear. This mixture, however, in the same 
vineyard is iiijiirioiiH to tlie quality of the wine; for although 
the several kinds of grapes do not ripen at the same time, 
yet they are all harvested together. 

GrajH's even of the same kind do not all rij)en at tlie 
pame jM'riod; the ditrerence of exposure, and the vei^etative 
vigor of the vine advance or retard the ripening several days. 
By gathering them all at once and subjecting them to the 
same fermentation, the wine obtained is far inferior to what 
it would be, if the grapes were culled, and only those press- 
ed which had arrived at maturity. 

In most of the French vineyards, harvesting is commen- 
ced early in the morning, and continued throughout the day, 
till the vintage is ended ; as fast as the grapes are brought 
in they are pressed, and the licpior thrown into the vat. Now 
it is well known, that grapes when moistened with dew or 
rain undergo a less speedy and thorough fermentation, than 
when they are well dried ; and it is likewise an established 
fact, that when the weather is hot durintr the vintacre, the 
fermentation of the grapes is not only more rapid but better 
than in cooler weather. 

It apj)ears, then, that grapes should not be gathered till 
the heat of tlie sun has dissipated the dew ; it \>, however, 
difficult to wait for all the favorable circumstances for a har- 
vest at the time of gathering grapes in our large vineyards ; 
they can only be seized ujx)n ior the manulacture of the 
most delicate and costly wines. The coarse red wines, like 
those from the banks of the Loire and the Cher, are sought 
for in connnerce only in proportion to the depth of their 
color, because they are principally used for mixing with 
white winos : the new wines are preferred for this pur|X)se, 
from their containing a |M)rtion of mucilage, which gives to 
the mixture a delicate taste, and those wines which have lost 
this principle in the casks are rejected, though better for 
drinking, because they are less fit to be mixed with dry 
white wines. 

By improving the fermentation of these coarse wines they 
would be rendered much better for drinkintr without any 
mixture ; but the only sale there is for them would be closed, 
as they would no longer be bought, as they are now, to form, 
by being mixed with the white wine of Sologne, the princi- 
pal drink of the j)eopl(^ of Paris. 

In some wine countries it is customary to pluck the 



FERMENTATION. 245 

grapes from the stalks, in others the must is fermentea with 
the stalks ; the mode should vary according to the nature of 
the grape, and the use for which the wine is designed. In 
the south, they pluck the grapes for wine that is destined for 
the table, and they do not pluck them for wine which is to 
be burned or distilled. 

M. Labadie, the proprietor of a vineyard, and a very en- 
lightened man, states that the wine made from the white 
grapes of Champagne is brisker, and less likely to become 
oily, when made of fruit that has not been plucked. 

Don Gentil is convinced, from his own experience in 
wine-making, that fermentation proceeds with a greater de- 
gree of energy and regularity in must from grapes that have 
not been plucked, than in that of plucked grapes. 

The stalks contain a slightly bitter principle, which is 
communicated to the wine, and improves the taste of such 
as is naturally, flat, and at the same time fermentation is 
facilitated by them. According to this, the fruit should be 
separated from the stalks whenever the must can be made, 
without any addition, to undergo a good fermentation, and 
produce first-rate wine ; and the stalks ought not to be re- 
moved from such grapes as usually afford only an ordinary, 
clammy kind of wine, which does not keep well. Nor 
should such grapes as contain a large portion of sugar be 
separated from the stalks, as they will then produce too 
sweet a wine. 

The temperature of the cellars in which the must is fer- 
mented is seldom equal to 12° of Reaumur, (z= 59° Fahr.) 
and the heat of the atmosphere, and consequently that of 
the grapes does not often indicate that degree ; and yet 
the must cannot be well fermented at less than from 52° to 
59° Fahr., and in order to insure a perfect fermentation the 
heat should rise thus high. 

The cellars might be heated by stoves, and the grapes 
placed in them before being pressed, till they had acquired 
the necessary degree of warmth ; or what would be better 
still, the must might be heated in boilers before being thrown 
into the vat; in this way fermentation would take place in a 
shorter time, and be more lively and complete. 

As soon as the liquor is in the vat, it should be closely 
covered over with boards and old coverlids, or, in prefer- 
ence, with the furniture belonging to the manufacture of 
wine. By intercepting all communication with the exter- 
nal air, the must is secured from being affected by the 
21* 



!24G CIIYMI3TRV APPLIED TO ACniCULTURC. 

changes of temperatiiro, which are unfavorable to fermenta- 
tion, the hoad oftho licpior is prcvcntfd from lK'Coniiri<^ sour, 
and at tlie same time a constant and ecjuahle lieat is kept up 
during the oj)eration. Shouhl the fermentati(m appear to re- 
lax, the li()U()r must \n; stirred uilli a l)ough, so as to mix 
with it tli(.' h;aven wliich has formed U})on tlie top, and by 
this a new imj)ulse will be given to the process. Good ef- 
fects arise also from keeping a bough of the vine immersed 
in the liquor by means of boards or a string. 

The ancients carefully separated all the various juices 
wliich they could obtain from grapes, and fermented them 
singly : the first, which was procured from the ripest grapes 
by the slightest pressure, furnished their finest wines, called 
by ihciu prof opcni, musti/iii sjwnfe flrflurns onfrrjucnn caJccn- 
tur uvd'. Baccius describes this process as practised by the 
Italians, thus : Qui primus liquor, nan calcatia uvis, dejluit, 
vinum rjficit i'i?\frinfU!n, uon inqui/idtuni frrrihus ; lacrymam 
vorant Itali ; rito jmtui if/onrum, ft valdc utile. 

When the wine has fermented sufficiently in the vat, it is 
put into hogsheads, and there undergoes an insensible fer- 
mentation, which completes the operations ; by being kept 
undisturbed it settles and becomes clear. 

In those countries where grapes arrive at perfect maturity, 
wine can be kept in the vat in which it is fermented, with- 
out any danger of alteration ; and this is done in most of the 
southern cantons; it is however necessary, in this case, that 
the joinings of the boards with which the vats are covered 
be plastered over with mortar, that the air may not gain ad- 
mittance. 

Wine makes better when in large quantities than when 
divided in casks ; but in those countries where the grapes 
contain less sugar, and where, after fermentation in the vat, 
the wine still contains much mucilage, if putting it into 
casks is delayed, the fermentation will very soon be followed 
by the second, and the product of this last is vinegar : the 
existence of alcohol and mucilage is sufficient to occasion 
this change. 

The casks which receive the wine from the vat sliould be 
arranged in a place where the temperature is cool and uni- 
form, and where they will not be e.xf)osed to being shaken or 
jolted. 

When fermentation has not been completed in the vat, 
it is contiiuH'd in the casks, and all tlie principles con- 
tained in the must, which are not susceptible of concurring 



FERMENTATION* 24t 

in the fermentation, are either precipitated to the bottom, or 
deposited upon the sides. All the methods adopted for clar- 
ifying wine are founded upon this principle. The mucilage, 
tartar, and extractive matter which must holds in solution, 
are only suspended in well-fermented wine, and are gradual- 
ly deposited from it. The burning of brimstone in the casks 
facilitates the formation of the deposit, and racking sepa- 
rates the deposited matter from the liquor. By the addition 
of isinglass or any similar substance to wine, all the particles 
which remain suspended in it are seized and united together, 
and can thus be removed. 

All these operations tend to free the wine from foreign 
substances, and to prevent it from becoming changed, and at 
the same time to preserve all the taste and good qualities 
which belong to it. The red wines lose a part of their col- 
oring matter by age, and, if the wine has been well clarified, 
this change can be accelerated by exposing bottles filled 
with it to the heat of the summer's sun. In this case the 
coloring matter is precipitated in pellicles, and the wine be- 
comes of the color of an onion skin, but undergoes no other 
change : I have seen this done in experiments upon the best 
wines of Languedoc. 

When wine is put into new casks, it dissolves a portion 
of the tannin and extractive matter contained in the wood, 
and is thus colored and decomposed, especially if the wine 
be not very strong. The liquor in this case acquires what 
is called the taste of the cask. The color which brandy 
receives in the cask is from these same principles. To 
obviate this inconvenience, the inside of the hogsheads 
should be charred ; the wine will then be preserved free from 
alteration. 

The most common degeneration of wine is its becoming 
sour, by which it is converted into vinegar : this does not, 
however, take place if the wine has been completely freed 
from the mucilage and extract contained in the must, but 
fermentation is seldom thorough enough to disengage entire- 
ly, and render insoluble these principles, especially if the 
grapes are not well ripened. 

This degeneration may be retarded, and even prevented 
by keeping the liquor in closely stopped casks set in a cool 
place, where they will be free from motion, as every shake 
of the cask mixes again with the wine the substances which 
have been precipitated from it. 

The acidification or acid degeneration does not take place 



248 ( HYMISTRY APPLIKD TO AnRICULTtnE. 

in sweet wine, as tliere still exists in tliat ;i portion of sug'ar 
which renders it incapable of undergoing any other than the 
vinous fennrntalion ; htit when this principle is rntircly de- 
conij)osed, a sullicicnt degree of lieat, the contact of the at- 
mosphere, and the presence of a little mucilage will cause 
the acidification of the greater number of wines. 

The acid degeneration generally takes place when the 
grapes do not contain sugar enough to decompose all the 
vegeto-animal part : it occurs necessarily in wine which 
holds in solution nuicilage and extract ; and this is always 
the case when the sugar contained in the grapes is not 
sufficient to develope much alcohol, and precipitate these 
substances. 

It appears, from well-confirmed experiments, that the con- 
tact of the air and the existence of mucilage and extract in 
wine containing but a small quantity of alcohol, will produce 
F[xintaneous acidification. 

Stahl states, that if the llowers of the rose-tree, or the lily 
of the valley be moistened with alcohol, and the vase con- 
tnining them shaken occasionally, vinegar will be formed, 
lie likewise informs us that when the acid of lemon is satu- 
rated with lime, if alcohol be thrown upon the remaining 
portions of the lemon juice, the mixture, when exposed to a 
gentle heat, produces vinegar. 

The best wine may be converted into vinegar by soaking 
or steeping green wood in it : the process described by Boer- 
haave is founded entirely upon this j)rincij)le : he enii>loyed 
for the purpose the branches of the vine and the stalks of 
grapes. 

The mash of grapes, the lees of wine, and the residuum 
of distillation well dried and moistened with a little alcohol 
and water, undergoes the acetous fermentation. The juices 
of most other fruits, as well as of gra))es, may be made, by 
fermentation, to produce a spirituous li(pior to be used either 
as drink, or to furnish alcohol by distillation. 

The practice of fermenting various kinds of bread corn, 
particularly rye and barley, has existed for a long time, 
and from them are produced, by distillation, the liquors 
that are most used in those countries where the vine is not 
cultivated. 

Since the culture of the potato has been so astonishing- 
ly extended in Europe, the uses of it have been multiplied, 
and it is now fermented for the purpose of obtaining alco- 
hol by distillation. The first process which was followed 



FERMENTATION. S49 

in this manufacture is still practised upon the banks of the 
Rhine, and in Germany ; by the second, for which we are 
indebted to modern chymistry, the fecula is converted into a 
saccharine substance, and thus rendered susceptible of the 
vinous fermentation. 

I shall describe concisely both of these processes, because 
they may be made to enter advantageously into a system of 
labor for an extensive farm, both on account of the liquor 
obtained, and of the food which is furnished for animals by 
the mash. 

The old method may be reduced to the two following 
operations. 

A cask which will contain about two English hogsheads 
is set up on one end, and a square opening made in the 
head, through which the potatoes are thrown in ; another 
small opening is formed in one of the staves on a level with 
the bottom of the cask, and serves for taking the potatoes 
out. The potatoes are boiled by steam introduced into 
the cask by a tube passing through the lower end of it 
As soon as the potatoes are boiled, they are crushed as 
perfectly as possible between two wooden cylinders, each 
of which is furnished at one end with a driving wheel, put 
in motion by a crank. The pulp of the potatoes is thrown 
into a tub where it is made to ferment : the vinous fermen- 
tation would not however take place in it, if it were not ex- 
cited by the addition of leaven ; the leaven used is made in 
the following manner. 

To 4 pounds of malt are added one pint of beer yeast, 
and about 44 pounds of the potato pulp ; these are worked 
carefully together and diluted with ten or eleven gallons 
of water at the temperature of 40° Reaumur, {=z 122° 
Fahrenheit,) and the vessel containing the mixture is cov- 
ered over. The paste thus made ferments and rises, and 
at the end of twenty-four hours, it is mixed with the body 
of pulp deposited in the vat, some hot water is thrown in 
upon it, and the whole is stirred constantly, till the tem- 
perature of the liquid stands at from 15° to 18° Reaumur, 
(= to 65f° and 72^° Fahrenheit,) and the specific gravity 
marks 6° or 7° upon the aerometer, (= specific gravity of 
1.044 to 1.052.) 

During fermentation, care must be taken that the tem- 
perature of the place should not vary more than from 20° 
to 25° Reaumur, {= to 77° and 88° of Fahrenheit;) and 
without this the fermentation will languish and never be 



250 CHYMISTRY APPLIED TO AGRICULTURE. 

complete. When all circiim.staiices are favorable, the fer- 
mentation may be terminated the third day, but it is most 
connnonly prolonged till the fourth or fifth. 

If the oj)eration be well conducted, the fermented licjuor 
will mark only to 1° of the aerometer, (= specific gravity 
of l.(K)() to 1.(107;) the more complete the fermentation is, 
the less will be the specific gravity of the licjuor. 

This action should never bo violent, as it is well known 
that in such cases the product is less than when it is slow 
and regular : whilst it is going on, all the fragments of the 
potatoes rise to the top and form a crust, which must be 
separated towards the middle to allow of the escape of the 
gas. 

In a manufactory where the processes are constantly going 
on, it is not necessary to form a new ferment for each opera- 
tion ; about three gallons may be reserved to be made use 
of when again required. 

Distillation should be .so conducted, that the alcohol may 
pass off equally and regularly, and this can only be done by 
a judicious management of the fire : the variations of the 
heat applied to the boiler accelerate or retard distillation, 
and consecjuently the alcohol in these two ca.«;es is not pro- 
duced in the same degree : it often happens when the fire is 
too forcible, that the liquid contained in the boiler is itself 
forced into the worm of the still. 

It is of importance in a distillery to have an abundance of 
water, both that the casks may be thoroughly rinsed after 
each operation, and for c(K)ling the worm of the still, as with- 
out this precaution a portion of the alcohol formed would be 
lost by evaj)oration. 

By this method four sacks of potatoes yield upon an aver- 
age Vi gallons and a fraction of brandy, at '20° (zn specific 
gravity of O.IKJ,"),) of the aerometer ; if all circumstances 
are favorable, they may afford lo gallons. 

When wines are dear and |x)tatoes cheap, the manufac- 
ture of brandy in this method, is found very profitable : in 
the year IH1(), the advantages arising from it were very great, 
and even under ordinary circumstances, it may be done with 
profit. 

The residuum of the di.stillation, mixed witli mustard or 
turnip rakes, forms e.xcellent food for horned cattle, and is 
eaten by them with avidity. 

The fecula or starch of potatoes was first converted into 
a fermentable saccharine substance by M. Kirchoff, of St. 



FERMENTATION. 251 

Petersburgh ; it was done by means of boiling it a long time 
in a weak sulphuric acid ; the result has been seized upon, 
and made the basis of an advantageous mode of rendering 
fecula fermentable, and extracting from it a spirituous liquor. 
This process has been brought to such a perfection in France, 
that the products of the establishments sustain a competition 
with those of wine and brandy, though the latter may be 
sellinor in commerce at a low rate. 

The first step is to mix, in a leaden boiler, concentrated 
sulphuric acid with water, in the proportion of 3 of acid to 
100 of wafer : the temperature of the liquor is then raised 
to boiling, and the fecula is laiade, by means of a hopper, 
to fall gradually into it : the mixture is then stirred forci- 
bly and the boilingr at the same time continued. After six 
hours the ebullition is stopped ; the acid is then saturated 
with chalk, and a sulphate of lime is thus formed and quick- 
ly precipitated. 

When all the deposit has formed, and the liquor become 
clear, it is carefully racked off and thrown into the vats in 
which it is to be fermented. These vats are five feet deep 
and four and a half in diameter ; they are situated in a place 
where they can be kept constantly at a temperature of from 
77° to 8S^° Fahrenheit. 

The density of the liquor should be from 7° to 8° of the 
aerometer, (= specific gravity of 1.052 to 1.060.) As soon 
as the fermentable liquor has acquired the temperature of the 
distillery, there is mixed with it 44 J- lbs. of the beer yeast 
which is brought from Holland : fermentation takes place in 
a short time and continues several days ; it sometimes re- 
laxes in energy, but in a few days the action is renewed with 
increased activity. 

1 cwt. of potatoes ought to yield from 5^ to 5f gallons, and 
this will be the case when the process is well conducted. 
Starch sells in Paris at from 8 to 9 francs (= about 144 and 
171 cents) per cwt. 

This brandy has neither a bad taste nor odor, and the 
manufacturers of liquors prefer it to that made from wine. 



252 CHYMISTKY APPLIED TO AGRICULTURE 

CHAPTER XVI. 

OF DISTILLATION. 

The art of distilling wine to extract from it the spirituous 
principle, has made known a new product, which is used not 
only as drink, but as one of the most useful articles employ- 
ed in the arts. 

The product of the distillation of wine is known in com- 
merce under the names of brandy, alcohol, spirit of wine, 
&.C. and the apparatus in which the process is carried on is 
called an alembic* 

The importance of vineyards has been greatly increased 
by the discovery of the art of distilling wine ; before that 
the vine was cuhivafed for no other purpose than that of fur- 
nishinii a strcnMheninur and ai/reeable drink : distillation 
disengages from this li(|uor a volatile, inflammable, spirit- 
uous principle, forming a much more active drink which has 
come into general use througliout nearly all Europe ; it is 
likewise used in the arts for dissolving resins and forming 
varnishes, to preserve fruits, dissolve the perfumes of plants, 
and to establish some new processes. 

Most of the white and a j)art of the red wines are now 
employed for distillation : tlie gfx)d red wines are reserved 
for the table. 

Before quitting so important a subject, T will sketch, in a 
few words, all which had been done in the way of di.stilling 
wine before the invention of the new apparatus, which has 
caused such a revolution in the art of distillation, that it may 
be said to have been created at the present day. 

The ancients had very imperfect ideas of distillation. 
From the evidence of Raymond Lully, Jerome Rubens, 
and John-Baj)tist Porta, there can be no doubt, that the 
ancients understood the art of extracting the odoriferous 
principle by the steam from water ; but they made use of 

* The names hrnndtj and snirit of icine, cnij)loyed to designate the 
two extremes of the same li<|iior as lluy are iband in commerce, 
have been supplied in the new ehynueal nomenclature by the g^eneric 
term alcuhul. However, as in connnon laniruai^e the names brandy 
and spirit of iriiir, are piven to substances ditterinjr widely in the uses 
to which they are applied, it is to l)e feared that commerce will not be 
willinjr lo cdinprrhcnd them under the same denomination; aa it is 
not enoujrh that the^- are of the same nature, if the price and the use 
estabUsh a wide difiercnce between tliem. 



DISTILLATION. 253 

nothing which deserved the name of apparatus. Dioscorides 
says, that in distilling resin it is necessary to collect the vola- 
tile particles upon cloths placed over the vase. 

The first navigators of the islands of the Archipelago 
procured fresh water by receiving the vapor of salt water in 
sponges arranged upon the vessels in which it was boiled. 
(See Porta, De DistiUatione, Cap. I.) 

The word distillation did not possess, amongst the an- 
cients, any signification analogous to the import of it at the 
present time : it was used by them as a generic term, com- 
prehending filtration, fluxation, sublimation, and all the sim- 
ilar operations to which we have assigned various names, and 
for each of which we use a particular kind of apparatus. 
(Jerome Rubeus, De Distillatione.) 

During the time of the republic and under the reign of 
the kings, the Romans appear to have known nothing of 
distilled spirit : Pliny, who wTote during the first century 
of the Christian era, makes no mention of it ; he has left 
us a very good treatise upon vinegar and wine, but he says 
nothing of distilled liquor, though he speaks of wine in 
all its forms : Galen, who lived a century after him, uses 
the word distillation in the sense which I have mentioned 
before. 

The art of distillation in all probability owes its origin to 
the Arabians, who have, from time immemorial, formed ex- 
tracts of the aroma of plants, and who brought their modes 
of proceeding successively into Italy, Spain, and the south 
of France : it even appears that the word alembic is found 
for the first time in their writings, and has its origin in 
their language ; it was used by them before the tenth centu- 
ry ; for Avicenna, who lived at that time, made use of it to 
explain the nature of the disease called catarrh, which he 
compared to a distillation in which the stomach is the cucur- 
bite, the head the cap, and the nose the beak by which the 
humors flow out 

Rhazes and Albucazin describe particular processes for 
extracting the aromatic principle from plants ; it appears that 
the steam was generally received into the cap of the still, 
which was cooled by wet cloths. 

It is evident that Raymond Lully, who lived in the thir- 
teenth century, was acquainted with distilled spirit and 
alcohol, for in his work entitled Testamentum novissimum, 
at page 2d of the Strasburg edition, 1571, he says : " Re- 
cipe nigrum nigrius nigro (red wine) et distilla totam 
22 



254 niYMISTIlY APPUFD TO ACRICLLTURE. 

aquam ardoiitom in l)alnno ; illam rcctitical)i.s qiioiisque 
niiio phlefTmate sit." He states tliat seven rectifications are 
cniplovcd, but that tlirre are sutlicient to render the alco- 
\u}\ intlarnniable, and to prevent its leaving any aqueous 
residuum. 

The sanio author shows elsouherc the mode of separating 
tlin water hy means ol' a dry fixed alkali. (See Bergman's 
Oiiu.<n(/(i p/ii/sica et chymirn, Leipsic edition of 1781, Vol. 
IV'. paire V'M .) Towards the end of the fourteenth century, 
Basil Valentine proposed the use of (piicklime for the same 
purpose. 

In all his works Raymond Lully speaks of a preparation 
of distilled spirit which he calls r/uinta fssfntlfi, whence is 
derived the word quititvsscnce : he obtained it by repeated 
cohobations made at a gentle heat during several days, and 
by redistilling the product. Raymond Lully and his suces- 
8ors attached great virtue to this quintessence, which they 
made the base of all their alchymical labors. 

Arnold of Villanova, a contem}>orary of Lully, speaks 
much of distilled sj)irit, but not in such a manner as to jus- 
tify the conclusion of his being the inventor of the process 
by which it was obtained ; he cannot however be denied the 
honor of having made the happiest aj)j)lication of the proper- 
ties of distilled spirit, and particularly of simple and com- 
pounded wine, both in medicine and pharmaceutical prepa- 
rations. (Arnnlf/i Villduovnni Prnxia : Tract at u s cic Vino; 
cap. J)r J'ofihus, etc.; edit. Lugduni, 15^6.) 

Michael Savonarola, who lived at the commencement of 
the fifteentli century, has left us a treatise {De cunp'rirnrfd 
Afji/d Vittc,) which contains some very remarkable things 
respecting distillation. He first remarks, that those who 
proceded him did not generally know the following process 
for distillation. This process consists in putting the wine 
into a metal boiler, and receiving the vapor in a pipe placed 
in a bath of cold water ; the condensed vapor flowed from 
tlie pipe into a receiver. 

Savonarola observes, that di.stillers placed their establish- 
ments near a stream of water, that thev might aiwavs have 
fresh water at their dis|>osal. The ancients called the spiral 
worm of the still vitis, on account of its windings. (See 
Jerome Rtdn-us.) For closing the joinings of the apj)aratus, 
they employed a lute made of lime and white of eggs ; or 
one of flour paste and paper. 

Savonarola adds, that in his day the use of glass cucur- 



DISTILLATION. 255 

bites was introduced, that the distilled spirit might be more 
pure ; and that they were covered with a cap which was 
cooled with wet cloths. He advises the use of large caps, as 
increasing the surface. (Cap. V.) 

The same author says, that the neck uniting the boiler 
and the head should be as long as possible, in order that the 
spirit may be produced at once, and adds, that one of his 
friends placed the boiler on a level with the ground, and the 
cap upon the roof of the house. 

Amongst the various means which he gives us, by which 
we may judge of the degrees of strength of distilled spirit, 
he mentions the following as being practised in his time. 
1st. Cloth or paper is dipped in the liquor, and then set on 
fire ; if the flame of the liquor burns the cloth or paper, the 
liquor is said to be of a good quality. 2d. The liquor is 
mixed with oil to see if it will swim, 

Savonarola treats at length of the virtues of distilled spir- 
it, and gives some processes for combining with it the aroma 
of different plants and some other principles, both by mace- 
ration and by distillation, and for thus making what he calls 
aqua ardens composita. 

Jerome Rubeus, who made many experiments in the way 
of distillation, describes two very curious processes, which 
he found, in fact, in ancient works : one of these processes 
consic-ted in receiving the steam into long, twisted tubes 
plunged in cold water ; the other, in placing over the cucur- 
bite a cap of glass, with a beak. It is remarkable that Je- 
rome Rubeus preferred the apparatus with the long tube, as 
he obtained by it, with a single distillation, very pure spirit 
of wine, which could only be obtained, with the other kind, 
by repeated distillations. (Z)e Distillatione, § 2, cap. II. 
edit, de Bale, de 1568.) 

John-Baptist Porta, a Neapolitan, who lived towards the 
end of the sixteenth century, published a treatise, Dc Dis- 
tillationibus, in which he viewed the operation in all its 
connections, and as applied to all the substances, which are 
capable of undergoing it : he described the different kinds 
of apparatus by which there might be obtained at pleasure, 
and by a single heat, distilled spirit in all its degrees of 
strength. 

The first kind of apparatus consists of a tube twisted 
spirally, and fitted to the top of the boiler ; the second is 
composed of caps placed one over the other, each one 
beincr furnished with an opening in the side, to which is 



2;>G CHYMISrnV AITLIKD to AClUCULTfRE. 

fitted a tube coinmuiiicnting with the receiver; he ob.servcfl, 
that by this means tliere can be obtained at pleasure all the 
degrees of rectification, since the afjueons ))articles are con- 
densed in the lower caps, whilst the spirituous parts rise to 
the upper one. These methods differ very little from those 
which, accordinj: to Jerome Rubeus, were in use amonj; the 
ancients, 

Nicholas Lefebvrc, who lived towards the middle of the 
seventeenth ccntiny, ])ublishe(l, in 1 (>.">!, a descrij)ti<)n of the 
aj)|)aratus witii which lie obtained, at a single operation, the 
purest alcohol. 

This apparatus is composed of a long funnel formed of 
several pieces joined together in zigzags ; one end of it is 
fitted to the boiler, and the other to the cap ; the beak of the 
cap transmits the vajx)r into a pipe, wliich passes through a 
cask filled with cold water ; in this pipe the vapor is con- 
densed and llows from it into a receiver. 

Dr. Arnaud, of Lyons, in his Introduction a la C/timie 
oil a la vraic P/ti/si(/ur, iinpr'une en 1(355, chez CI. Prost, 
a I. yon, has given us some excellent instructions in re- 
gard to the construction of furnaces, the composition of 
riues, the mode of regulating the fire, calcination, and 
distillation, which he calls a moist sublimation. He advises 
the use ol t^hallow boilers as facilitating evapoiation ; he 
speaks of the conversion of distilled spirit into the spirit 
of wine, by rei)eated distillations in a water bath, such as 
is now employed for distilling those substances, the spirit- 
uous portions of which are vaporized at a degree of heat 
less than that of boiling water. He also speaks of the vaj)or 
or dew bath. 

John Rodolj)!! Glauber, in his treatise entitled De- 
script io Artis JJi.<ti/lat()rifn norrr, printcMl in Amsterdam 
in 1()5H, by John Janson, makes known to us some pro- 
ceedings, in which we find the germ of most of the opera- 
tions, which are now carried to such j>erfection amongst 
us. One of them consists in transnutting the va|>or 
which escapes by distillation into a vase surrounded with 
cold water : the vajw^r which is not condensed in this first 
vessel, passes through a IkmiI tube into a second, from that 
to a third, and .so on till the whole is perfectly condensed. 
It is evident, that by means of such an apparatus, sj)irits 
of wine of dini'rent degrees of rectification may be ob- 
tained, according as the condensation takes j)lace in the 
first, second, or third of the vases, j)liinged in cold water. 



DISTILLATION. 257 

In another kind of apparatus, he placed a retort of copper 
in a furnace ; the beak of the retort passed into a close cask 
filled with the liquor which he wished to distil ; a tube, fitted 
into the upper part of the cask, was joined to a worm placed 
in another cask, which was filled with cold water. By this 
arrangement, the liquid contained in the first cask was con- 
tinually falling into the retort, where it was heated, and thus 
the whole contents of the cask were at length raised to a 
sufficient degree of heat to produce distillation, and thus a 
considerable volume of liquor was heated with a small fur- 
nace, and at a trifling expense. Glauber applied this inge- 
nious apparatus to heating baths. 

Philip James Sachs, in a work printed at Leipsic, in 1661, 
under the title of Vitis vinifercB ejtisque Partium Considered 
tio, &c., has given us a complete and very valuable treatise 
upon the culture of the vine, the nature of the soils, cli- 
mates, and exposure adapted to the growth of it ; the 
manner of making wine ; the comparative wealth of differ- 
ent nations in this article of culture ; the differences and 
resemblances of the several methods used amongst each 
of them ; the distillation of wines, &c. In the last chapter 
we see what will only detain us for a moment, that the an- 
cients had many methods of extracting spirit of wine, 
and that these consisted entirely either in vaporizing it at 
a gentle heat, depriving wine of its water by calcined alum, 
putting moistened cloths over the alembic, placing ice upon 
the cap of the alembic, that the most subtle vapors might 
not escape, or, finally, in terminating the boiler by a very 
long neck. 

The same author speaks also of the quintessence, 
quinta essentia, and gives various modes of extracting it. 
" Ut vero spiritus vini alcool exaltetur, variis modis tenta- 
runt chimici ; quidam multis repetitis cohobationibus ; ali- 
qui, instrumentorum altitudine ; alii, spongia alambici ros- 
trum obturante, ut, aqua retenta, soli spiritus transirent; 
non multi, flamma lampadis, ut ad summum gradum depu- 
rationis exaltaretur." 

Moses Charas, in his Pharmacopma, printed in 1676, 
describes the apparatus of Lefebvre, and adds some im- 
provements to it ; he adapts a refrigerator to the cap. We 
may still see, in the Elemens de Chimie of Berchusen, 
printed in 1718, and in those of Boerhaave, which appeared 
at Paris in 1733, several processes detailed, by which very 
pure alcohol may be obtained at a single distillation; but 
22* 



25S CHYMISTRY APPLIP:i) TO AGRICCLTL'RE. 

in all of them the vajior passes tlirough long tubes, that 
the a(iiieou9 particles may be condensed, and that the last 
result may not be received till it is as light and pure as 
possible. 

Subsequently to these authors, many others have written 
upon the subject of distillation, and have ])roix)sed and 
executed many alterations up<Hi their nx'tliods ; instead, 
however, of improving upon the happy idea of their pred- 
ecessors, wlu) aimed at obtaining at pleasure all the de- 
grees of alcoliol by successive condensations of the watery 
particles mixed with the alcohol, they confined themselves 
to varying the form of the boiler, the retort, or the worm, 
and tluis the art of distilling was nearly in a retrograde state 
for almost a century. 

This art was stationary a sliort time since, when a process 
was generally adopted, which, though far from being found- 
ed ujKHi true princi])les, produced the desired effect. In this 
process the alcohol of the diticrent degrees of strength was 
obtained by repeated distillations. Such was the state of 
the art towards the end of the last century ; at tliat period 
the apj)aratus most generally employed for distilling was 
comjK)sed of three pieces ; the metal used was copper ; 
the boiler, which contained about 50 gallons of wine, was 
contracted in size towards the upjxjr part ; a cap was adapt- 
ed to the orifice, and communicated by a long pipe with a 
worm ; the worm was placed in a cask which was kept full 
of cold water, and thus condensation of the alc<jholic vapir 
was prcxiuced. 

This coarse apparatus ]X)ssessed many defects, the first 
of which was, that ail the vajxirs raised by the action of 
the fire passed into the worm, where they were condensed; 
thus the a^pioous particles were mixed with those of alco- 
hol, and flowed with them into the receiver, forming a 
weak distilled spirit, which required to be submitted to a 
.second distillation before it could be brought to a due degree 
of Htrenglh, 

The second inconvenience arising from this apparatus, 
was the incompleteness of the condensation ; for as the 
water in the cask »oon became heated, there consecpiently 
ensued a great loss of alcoholic vapor, which passed off 
into the atmosj)here of the <listillery. 

The third fault was, that, as aJl the vapors, which rose 
from the boiler, passed innnediately into the worm, where 
they were condensed, it was necessary so to regulate the 



DISTILLATION. *^59 

fire, that the alcoholic, particles alone might be evaporated; 
a few moments of too great heat were sufficient to cause 
the ascension of a great mass of aqueous vapor, by which 
the alcohol was rendered deficient in strength ; the necessi- 
ty of watching the fire, therefore, made the operation a very 
difficult one. 

The union of so many faults in the apparatus, rendered it 
impossible to extract the last portions of alcohol remaining 
in the wine, without their being loaded with an immense 
quantity of aqueous particles : this last product of distillation 
was carefully separated under the name of small water, and 
redistilled with a new portion of wine. 

The spirit obtained by the above process always has a 
burnt taste, and is rarely very clear ; this arises from the 
difficulty of regulating the fire, and the still greater difficul- 
ty of obtaining, without increasing the heat too much, all 
the alcoholic particles contained in the wine. 

If to the above-mentioned faults we add, that the furnaces 
of these alembics were badly constructed, that they present- 
ed no means either of regulating the heat, or of applying it 
equally to the whole body of the liquor, we shall see that the 
art of distilling was yet in its infancy. 

I was aware of these defects, and attempted to correct 
them, and in consequence I caused to be made large boilers 
of but little depth, that as great a surface as possible might 
be presented to the fire ; I surrounded the cap with a bath of 
cold water ; this produced the first condensation, and separa- 
ted the aqueous particles, which fell back in drops or streams 
into the boiler ; I increased the number of windino-s in the 
worm, and enlarged the bath-cask, that the water might not 
so soon become heated. These alterations were approved of, 
and distillation was established upon these principles. My 
apparatus and that of M. Argand, who had wonderfully im- 
proved the furnace, was employed with success during fifteen 
or twenty years. 

In the first years of the present century, the art of distilla- 
tion was established upon new principles, and it has gone far 
beyond all that was before known and practised. A chymi- 
cal apparatus, by means of which vapors or gases were made 
to pass through liquids which were to be saturated with them, 
gave to Edward Adam the first idea of his apparatus for dis- 
tillation ; a knowledge of the fact that aqueous vapors are 
condensed at a degree of heat which does not effect a like 
change in alcoholic vapor, furnished him with the means of 
completing his apparatus. 



260 ClIYMISTRY APPLIED TO AGRICULTURE:. 

The chymical app.iratus suggested to Adam the idea of 
conducting, by the aid of a copper tube, tlie vapor which 
rises from a boiler of wine placed over the fire of a fur- 
nace, into a second boiler of the same licpiid, which is 
thus heated to the boiling j)oint : the vapor from this second 
boiler may be carried into a third, in which ebullition will 
likewise take place ; and thu« by means of a fire kept under 
one boiler, distillation may be carried on in two or three, 
provided they are well closed. 'J'his mode of transmitting 
heat is now practised in most foreign distilleries, and it is 
called luntinff Uy steam. 

Edward Adam, by the process just detailed, made a 
great saving of fuel, and was sure that the spirit obtained 
would always be free from a burnt taste. lie also saved 
time and labor, for the workman whose business it was to 
attend one furnace, accomplished much greater results, 
than if that fire caused the evajvjration of but one boiler. 
These were certainly great improvements, but it was 
necessary to go still further, and to find the means of ob- 
taining alcohol in its greatest possible purity by freeing it 
from all acpieous particles, and this he did by applying to 
his apparatus the second principle which we have already 
specified. " By making," he says, " the alcoholic vapor 
which rises out of the last boiler pass into vessels im- 
mersed in a bath of cold water, the aqueous vapor will be 
condensed, and I can then bring it back again into the 
first boiler, to be there redistilled, whilst the alcoholic va- 
por will pass out of these vessels, without being con- 
densed, into the worm, where it will undergo condensa- 
tion."' 

Proceeding upon this reasoning, founded upon positive 
facts, he adn[)ted a tube to the upper part of the last boiler; 
this tub«3 conducts the vapor into u first condenser, which is 
of a si)herical form and immersed in a water bath ; in this, 
a part of the acpieous vapors are resolved into a liquid form, 
and this li<juid is carried by a pipe into the wine of the first 
boiler, to be redistilled and deprived of the small j)ortion of 
alcohol which it still holds in solution ; the va|X)rs which 
cannot be condensed in the first receiver pass into a second, 
where a now condensation takes place in consequence of 
the temperature being less elevated ; from the second it 
goes into a third, and thence into a fourth ; that which is 
condensed returns, as I have just said, into the boiler, wliere, 
by a new distillation, it is deprived of ail its remaining spir- 
ituous portions. 



DISTILLATION. 261 

The vapor in passing through the condensers gradually 
loses its heat, and thus the water is precipitated, and the al- 
cohol being deprived of nearly all the water which had risen 
with it, when it is at length condensed in the worm, marks 
the highest degree of rectification. 

We see, from the foregoing statement, that by this process 
there can be obtained at will, and by a single operation, all 
the degrees of rectification found in commerce ; each con- 
denser yields a different degree, and, by withdrawing suc- 
cessively the product of each one, we shall procure a spirit- 
uous liquor, varying through all the degrees from brandy to 
the purest alcohol. By conducting the vapors directly into 
the worm, without causing them to pass through the inter- 
mediate condensers, that degree which forms good brandy 
of commerce is produced. 

Such are the principles which chiefly constitute the pro- 
cess of Edward Adam ; but independently of the applica- 
tion of these principles, he has added some improvements to 
his apparatus, which render it more perfect. 

By the aid of stop-cocks and pipes, he directs the vapor at 
pleasure into a small worm of experiment, there to undergo 
condensation, in order that the degree of rectification may 
be judged of as often as necessary. He also interposes a 
worm between the condensers and the worm which is in the 
water-cask ; the upper worm is immersed in the wine, which 
receives from it a degree of heat which hastens its ebullition 
when the boilers are filled. This first worm so condenses 
the alcoholic vapor, that it flows liquid into the second worm, 
and heats but little the water bath in which the second 
worm is immersed. 

From these arrangements there arise three great advan- 
tages : in the first place, the wine to be distilled is heated 
without material expense ; in the second, the water bath is 
not obliged to be renewed ; in the third, the alcohol is al- 
ways obtained cold, and all danger of loss or evaporation is 
avoided. 

M. Edward Adam formed successively several large es- 
tablishments at Cette, Toulon, Perpignan, &c., and secured 
a patent right to insure the enjoyment of the advantages 
arising from his inventions ; his success, however, very soon 
awakened the attention of other distillers ; his results were 
such, that they could no longer compete with him, and ac- 
eordingly they everywhere made attempts either to imitate 
or vary his process. 



2(32 CHYMISTRY APPLIED TO AGRICULTURE. 

The greatest number of the attempts that were made were 
based u[)on the fundamental idea, that alcoholic v.apor could 
not be condonsod at so low a temperature as steam. The 
apparatus of Hdward Adam was immense and very costly ; 
others sought to reduce the dimensions, and thus to place it 
vv'ithin the |>ower of a greater number. 

Isaac Berard of Orand-Ci all argues (department of Gard) 
produced, a short time after, a more simple apparatus 
than that of Adam, and which obtained the preference over 
his : instead of covering the l)(>iler witli a cap, as had been 
formerly done, he surmounted it by a cylinder, the interior 
of which was divided into several compartments communi- 
cating with eacli other by small openings : the vajwr aris- 
ing from the boiling wine was transmitted into these cham- 
bers, where the aqueous particles, being condensed, were 
carried back into the boiler by channels for that purpose, 
whilst the alcoholic vajwr passed into a condensing cylin- 
der which was immersed in a water bath : this cylinder 
was divided transversely, by plates of copper, into four or 
five chambers, communicating with each other by open- 
ings, so that the vapor might be made either to pass 
through all of them before entering the worm, or it might 
be conducted thither after havinor cjonc through two or 
three. The vapor was so far purified in its passage through 
these chambers, that, when at length condensed in the 
worm, the alcohol marked from 'Wf to 38°, (=: specific 
gravity of 0.S47 to 0.842,) whilst that which was carried in- 
to the worm without going through the chambers, when con- 
densed, marked only from 20"^ to 25°, (:= sp. gr. of 0.935 to 
0.90() :) all the intermediate degrees were obtained at pleas- 
ure according to the number of chambers through which the 
vapof was made to pass. 

The apparatus of Berard appeared so simple and so ad- 
vantageous, that it was generally adopted : Edward Adam 
attacked tlio author of it as a countcrft'itcr ; the expensive 
and tedious suits which he was obliged to sustain against 
Berard and many others, turned him aside from his busi- 
ness, and tliis man, to whom we owe nearlv all the art of dis- 
tilling, died almost in poverty, a prey to disappointment and 
chagrin. 

Nearly at tlie same period M. Cellier, of Blumcnithal, con- 
ceived th(! haj)j)v idea of economizing time and fuel by 
multiplying in<lefinitely the surface of wine submitted to 
distillation : to effect this, he caused the vapor which es- 



DISTILLATION. 263 

caped from the boiler, to circulate under numerous shallow 
vessels of copper placed one above the other, and each con- 
taining a portion of wine of about an inch in depth. The 
vessels were constantly supplied with cold wine which flow- 
ed from one to the other, allowing the alcohol to evaporate 
from them ; the remainder flowed into the boiler to be again 
distilled. The liquor, deprived of all its alcohol, escaped 
continually from the boiler by an outlet in the side. 

This process, improved by M. Derosne, is very expedi- 
tious, and the expense of fuel when compared with the ef- 
fects produced, is small. 

This method of distilling is called continual distillation. 

The apparatus of M, Cellier, though protected by a patent, 
was imitated, and Cellier experienced the same fate as Ed- 
ward Adam, in consequence of the suits he was obliged to 
institute against the counterfeiters of his apparatus : so in- 
sufficient is the law regarding patent rights. 

Since that time distillatory apparatus has received an 
almost endless variety of alterations ; the same general 
principles, however, prevail in the construction of all of 
them.* 

Some have directed a current of heat, proceeding from a 
single fire-place, under several boilers arranged side by 
side : others have varied the number and form of the con- 
densers : several have made arrangements by which the 
filling of the boilers was facilitated ; for ascertainng the 
time when the liquor no longer contained any alcohol ; 
for heating the wine subjected to distillation without much 
expense ; &lq„ 

These successive discoveries have afforded the means of 
distilling, in greater perfection than before, the mash of 
grapes, fermented grains, beer, cider, &l,q,. 

By applying to these fermented substances the simple 
heat of aqueous or alcoholic vapor, the alcohol disengaged 
is of the best kind, because the liquor, not being exposed 
immediately to the action of the fire, does not imbibe any 
empyreumatic flavor ; neither is the boiler burned as it is 
in the distillation of the mash of grapes or grain over the 
naked fire. 

Being obliged either to make choice amongst the kinds 
of apparatus in general use, or to form a new one com- 

* A work published in two volumes by M. Lenormand is a complete 
treatise upon the subject, and may be read with advantage. 



204 C1IVM1>111V AVriALD TO AGIUCL LTIKE. 

posed of all the actual imi)rovrni(Mils wliicli have been suc- 
cessively iiitro(hic(Ml, 1 adopted the following. 

A boiler capal)lo of holding about 132 gallons of wine 
is placed over a furnace ; to the upper j)art of the boiler is 
aflixed a pij)e, which carries the vapor into a second l)oiler 
containing 106 gallons of wine, in which the pipe is im- 
mersed about six inches. With the upper part of this 
Kccond boiler there is connected a tube, which transmits 
the vapor into a cylinder five feet in length and fifteen inches 
in diameter; the inside of this cylinder i.s divided into four 
chanil)ers, by plates of copper ; these chambers or cavities 
communicate with each other, by small orifices in the upper 
part of the plates : the cylinder is immer.sed in a trough of 
cold water ; the water of this trough is renewed at the end 
farthest from the boilers. 

The va}X)r which is not condensed in passing through the 
chambers of the cylinder, is carried through a pipe into a 
worm immersed in the wine, and thence into a lower w'orm, 
which is cooled in water. The current of heat, after havinsr 
heated the first boiler, passes under the second to facilitate 
the ebullition of the licjuid. 

Such is the general arrangement of the apparatus ; but in 
order to render the use of it as sure as it is easy, it is neces- 
sary to enter into some particulars concerning its construc- 
tion. 

1. In the top of the boiler there is a small pipe with a 
Ftop-cock ; upon turning the cock a jet of vapor is thrown 
out, to which a lighted taper is ap])lied; if the vaj)or takes 
fire, the distillation is not completed ; if the contrary be the 
case, it is completed. 

2. There is, at the lower part of the boiler, a large pipe 
with a stop-cock for drawing off the residuum or vinasse. 

3. A lateral stop-cock for ascertaining when the boiler is 
filled to a sufficient height. 

4. A valve, of an inch and a half in diameter, in the top 
and at some inches from the place where the boiler is con- 
tracted ; this is used in cleansing or filling the l)oiler. 

At the bottom of each chamber of the condensing cylin- 
der, there should be a pipe to carry off the condensed 
licjuid ; these ])ipes should communicate with a large tube 
by which the licpior will be conveyed into the bottom of 
the first boiler; that this may be done with the greatest 
ease and regularity, it is advisable that a stop-cock be 
placed in each of the pipes at the distance of about an 



DISTILLATION. S65 

inch from their insertion into the common tube. As to the 
upper worm, since the wine which serves it as a bath may 
become heated to a degree sufficient for producing alcoholic 
vapor, it is necessary that the cask in which it is contained 
should be hermetically closed, and that there should be, in 
the top, only a socket to permit its being filled, and a tube 
by which the alcoholic vapor may be transmitted to the bot- 
tom of the second boiler. A large stop-cock placed lateral- 
ly at the bottom of the cask serves for drawing off the hot 
wine whenever the first boiler is to be filled. 

The mechanism of this apparatus is easily understood. 
When the two boilers and the cask containing the worm are 
filled, the liquid in the first is heated to the boiling point ; 
the second is acted upon by the heat which escapes from the 
fire of the first. The vapors arising from the first are trans- 
mitted to the second, where they are condensed, and give 
out all their heat to the body of wine into which they pass. 
This liquid is soon raised to the boiling point, and all the va- 
por arising from it passes into the condensing cylinder, the 
coldness of which condenses the aqueous particles, and with 
them a portion of alcohol. This condensed fluid is returned 
by pipes into the bottom of the first boiler, where it is deprived 
of its alcohol by a second distillation. That portion of va- 
por which remains uncondensed, passes into the first worm, 
where it is reduced to the liquid state, and this liquid upon 
passing into the second worm is deprived of all its heat. By 
this apparatus excellent alcohol, marking from 36^ to 38° of 
the hydrometer, (:= specific gravity of 0.847 to 0.837,) may 
be obtained at a single heatinor. 

As the purity of the alcohol is increased by the coldness 
of the water in which the condensing cylinder is immersed, 
it is necessary that this should be changed as often as pos- 
sible. 

It is easily seen, that if the tube which conveys the vapor 
from the second boiler into the condensing cylinder, trans- 
mitted it immediately into the worm, the product would be 
common brandy ; but as it is freed from watery particles by 
means of the condenser, it yields a spirituous liquor of the 
higher degrees. 

If, instead of filling the first boiler with wine, it be filled 
with water, and the second with mash of grapes or with fer- 
mented grain, the operation may be conducted in the same 
manner, and alcohol extracted without any hazard of burn- 
ing the boiler. 

23 



2(>6 r»YMlSTRY API'I.ir.D TO AGRICULTURE. 

This apparatus presents no danger of bursting ; tlie va- 
\K>T has suclj free issue from all parts, that the compression 
is never great enough to occasion an explosion ; it is very 
easily used, and may without dilliculty be made to under- 
go three or four heatings every day, and to furnish from 
201 to 290 gallons of good brandy, from wine yielding from 
i to i. 

Neither all kinds of wine, nor fermented liquors general- 
ly, yield the same (juantity or quality of alcohol : the wines 
of the south allorcl more brandy than those of the north ; 
from the first there may be obtained ^ ; the average is ^ ; 
whilst from those of the centre it is ^, and from the north 
from ^ to y'jj. 

There is great difference in the strenorth of wines of the 
same country. Grapes raised in a light, dry soil, and with 
a southern exjx)sure, yield wine highly charged with alco- 
hol, whilst grapes of the same kind growing in a moist and 
strong soil, and having a different exposure, furnish wine 
containing but a small portion of alcohol. 

The strength of wine depends upon the quantity of alco- 
hol contained in it, but its quality and its price caimot be cal- 
culated in the same way : the odor and taste which render 
any kind of wine valuable, are qualities entirely independent 
of the (juantity of alcohol it contains. 

Wine rich in alcohol is strong and generous, but it has 
neither the mellowness nor the perfume which characterize 
some of the other kinds of wine. 

The brandy distilled from white wine has a better taste 
than that from red wine : in the south the red wine is almost 
everywhere distilled ; but the brandy made there, though 
very abundant, is less esteemed than that procured fro'.n the 
white wine of the west. 

Wine which has begun to turn sour furnishes but little 
brandy, and that of a bad (piality ; it is therefore necessary 
that wine which is to be distilled should have been well fer- 
mented and kept ; and this explains the idea entertained by 
many distillers, that wine should be distilled as soon as it is 
completely fermented : this opinion however is unfounded, 
excepting so far as it regards wine of an inferior (juality ; 
strong, generous wine, which has been well fermented, and 
well clarified, may be distilled at any age. 

Wlu'n wine hiLs been selected for distillation, the process 
iri carried on in the following manner. 

The b<jil(>r must, in the first place, be carefully washed. 



DISTILLATION, 267 

OTj supposing one distillation to have been previously termi- 
nated, the stop-cock must be opened to allow the residuum 
or vinasse to run out : through the valve in the top a stick 
must be introduced with which the liquid can be stirred, and 
every thing removed which would tend to form a crust upon 
the inside of the vessel. The stop-cock may then be closed 
and water thrown into the boiler ; this, after being stirred 
and allowed to remain some time, is to be drawn off through 
the stop-cock. 

To show the importance of this preliminary operation, 
it is sufficient to observe, that if it be neglected, the sides 
of the boiler will become encrusted with tartar and lees, 
which will speedily give to the alcohol a disagreeable 
flavor ; and which will likewise occasion the burning of 
the copper, since it cannot be immediately moistened by 
the liquor. 

As soon as the boiler is thoroughly cleansed, it may be 
filled about three-fourths full of wine ; but before pouring the 
wine in, the side stop-cock must be opened to allow a passage 
for the air contained in the boiler, which would otherwise 
throw out the wine, and likewise for ascertaining wh^n the 
charge is complete : as soon as there is a suitable quantity of 
wine in the boiler, the fire is kindled. 

The progress which the vapor makes through the different 
parts of the apparatus, is judged of by the heat which they 
successively acquire, as it passes through theiiL 

The first product ia alcolaol possessing neither an agreea- 
ble odor nor taste, and which is removed to undergo a sec- 
ond distillation. The alcohol which follows this is highly 
concentrated and of a good quality : the grade of it is de- 
termined by the hydrometer, and this instrument is therefore 
placed at the opening of the receiving vessel, (bassiot,) to in- 
dicate the strength of the alcohol during the whole time of 
the operation. For some time the hydrometer indicates 
nearly the same degree ; but as the heat of the apparatus and 
baths increases, the aqueous particles are less perfectly con- 
densed, and consequently the alcohol, being less concentra- 
ted, is inferior in strength. 

When the alcohol begins to fall below 20°, (= sp. gr. of 
0.935,) the small stop-cock in the top of the boiler is opened 
from time to time, and a lighted taper is presented to the va- 
por issuing through it ; when this vapor will not take fire, the 
operation is terminated. 

If the same Jowness of temperature could be preserved 



208 CHYMISTRV Al'ri.Il.l) TO A^.RICULTURE. 

in the watcr-batli of tlic coiulciisors, and in tlic liquid in 
wliich tlie worm is immersed, the product of the whole ope- 
ration woulil he of the same specific frravity ; the detrrees 
may tluTcfore be raised again when they begin to sink, by 
changing the baths. 

When tiie operation is completed, the fire is covered, tlie 
re-<i(lunm ol' tlie wine removed, and the boiler cleansed and 
again filled. 

Though tin; alcohol distilled in the course of the opera- 
tion is not all of the same degree, it may be made 
8o by mixing the several portions ; the better way how- 
ever is to redistil that which is produced last, and thus 
raise the whole to the hiijhest degree known. There is no 
need in any case of having recourse to what is called the 
water-bath. 

Alcohol should be colorless and destitute of any un- 
pleasant odor ; any bad (iualiti(\s it may have, may be re- 
moved by a second distillation carefully performed; in- 
deed it is often enough to tiltratc it through well burnt 
charc^)al reduced to a very fine jK)wder. The bad quality 
of alcohol arises almost always from want of care in the 
distillation of it, or from a fault in some one or more of 
the ditlerent parts of the apj)aratus : sometimes, however, it 
happens th a it is owing to the wine's having begun to turn 
sour. 

As fast as the vessels which receive the alcohol are full, 
they are emptied into oaken casks ect in a cool place to pre- 
vent evaporation : from the casks the liquor acquires a yel- 
lowish color, but is unchanged in any other respect. Bran- 
dy loses by age the burnt taste which it often has when new, 
and becomes milder and more agreeable. 

The instruments made use of for ascertaining the specific 
gravity of alcohol, do not give it with mathematical precision, 
but near enough for conunercial purpo.>^es: previous to the 
knowledge of these instruments the methods made use of 
were very inexact. 

The regulation of 17"-'.) ordered powder to be put into a 
spoon an«l covered with alcohol ; the sjxjon was then placed 
over the fire, and the strength of the alcohol was judged of 
by the kindling or not kindling of the j)owd(T. To obtain by 
this method exact results, it was necessary that the quantity of 
powder and of alcohol should be always the same ; for a larger 
])roj)otti()ii of si)irit would leave, after combustion, a great- 
er (juantity of water, and this would prevent the powder from 
taking fire. 



tJlSTILLATlON. 269 

The carbonate of potash has likewise been employed as a 
test, from its dissolving with more or less ease according to 
the quantity of water contained in the alcohol. 

In the year 1770, the Spanish government ordered oil to 
be made use of as a test ; the process consisted in letting a 
drop of oil fall upon the alcohol ; the strength of the li- 
quor was determined by the depth to which the oil sunk 
m it. It is evident that this method is very inexact, as the 
depth to which the oil will sink must depend much upon the 
size of the drop, and the height from which it is allowed to 
fall. 

In the year 1772, Messrs. Borie and Pouget arrived at 
some conclusions, which ended in giving to commerce a hy- 
drometer of a sufficient degree of precision to prevent errors 
of much consequence in estimating the specific gravity of 
alcohol. 

After having made some very exact experiments upon mix- 
tures of pure alcohol with water, and upon the effect of tem- 
perature at all possible degrees of concentration, these two 
learned philosophers adopted an instrument which allows for 
the variations of temperature. This hydrometer has con- 
tributed not a little towards raising the reputation of south- 
ern brandy in the north, by furnishing it to commerce of its 
full strength. 

So necessary is the use of a good hydrometer in commerce, 
that I have seen for more than five years our Languedoc 
merchants buying Spanish brandy, of which the strength was 
not uniform, and confining themselves to rendering it of the 
degree suitable for being sent into the north, and all the 
other countries where it is consumed. 

In the south, where the greater part of the brandy distrib- 
uted in commerce is manufactured, it is known under differ- 
ent names, which are given to various degrees of rectifica- 
tion. That which marks from 20° to 22° (= specific gravi- 
ty of 0.935 to 0.923) is called Holland proof . 

This first quality, when more concentrated, and re- 
duced to I by the subtraction of the water contained in it, 
takes the name of three Jive. When deprived of | or ^ more 
of its aqueous principle, it is known as three six and three 
seven. 

At Paris, and elsewhere, the hydrometers of Baum6 or 
Oartier are employed for ascertaining the grade of alcohol: 
these instruments are less exact than that of Borie, but are 
sufficiently so for commercial purposes, 
^3* 



270 CHVMISTRY APPLIED TO AGRICULTURE. 

Alcohol is used as drink ; it is employed for dissolving re- 
sins, and it enters into the composition of drying or spirit- 
of-irini rarnis/us. 

AIcoIjoI serves as a vehicle for the aromatic principle of 
plants, and then takes the name of the spirit or essence of 
such or such a j)laut. 

It is made use of by apothecaries for dissolving the re- 
sinous gums, and these solutions are known by the name of 
tirif tur(s. 

Alcohol forms the basis of all those drijiks known by the 
name of liqueurs, which are only alcohol sweetened and fla- 
vored with any aromatic substances which will give it an 
agreeable taste and perfume. 

All vegetable substances which have undergone the spir- 
ituous fermentation yield alcohol upon distillation, but the 
quantity and the quality vary much. 

Alcohol made from cider has generally a bad taste, be- 
cause the fermented liquor contains much malic acid, a part 
of which rises with the alcohol, and remains mi.xed with it. 

Alcohol produced from the fermented liquor of wild cher- 
ries is stronger than that distilled from wine, and is known 
under the name of kirsrJurassrr. 

Alcohol distilled from fermented sirup of sugar is called 
rum and tafia. 

Pallas saw, among the Kalmucks and Tartars, the sour 
milk of cows and mares distilled : the acidification of the 
milk is facilitated by the addition of leaven, made of coarse 
salted meal, or with rennet made of the stomachs of lambs : 
the milk which is destined to be made into brandy is never 
skimmed. Distillation is performed in boilers covered over 
with wooden caps, and the product is received into vessels 
which are cooled by surrounding them with very cold 
water. 

In almost all known countries, brandy is distilled from 
grains, but it is difficult to obtain it from them free from 
some bad taste occasioned by the burning of the glutinous 
fermented matter which adheres to the sides of the boiler, 
and communicates its flavor to the licpior : this taste is dis- 
guised by mixing juniper berries witii the fermented grain : 
the taste of the berries predominates in the liquor, and it is 
known under the name of juniper brandy or gin. 



MEANS OF PREPARING WHOLESOME DRINKS. 271 

CHAPTER XVII. 

ON THE MEANS OF PREPARING WHOLESOME DRINKS FOR 
THE USE OF COUNTRY PEOPLE. 

A GREAT portion of the inhabitants of the country have 
no other drink than the water furnished by wells, cisterns, 
and pools. 

The water of wells varies much in quality, according to 
the nature of the soil through which it filtrates : if that be 
granitic, or formed by layers of primitive calcareous earth, 
the water is excellent ; when it passes through beds of chalk 
or gypsum, it is bad : in the first case, the rain-water pre- 
serves all its purity ; in the second, it dissolves, or carries 
with it, in a state of extreme division, a portion either of the 
sulphate or the sub-carbonate of lime. Water of this 
kind is heavy, very ill adapted to the cooking of leguminous 
vegetables, or to being used in washing, as it decomposes 
soap, instead of dissolving it. 

The best well-water is liable to be rendered impure by the 
filtrations of the juices from the dung and from the various 
substances which are decaying upon the surface of the soil 
in the vicinity : this evil is often found to exist in the coun- 
try, where wells and dung heaps are not unfrequently to be 
seen in the same enclosure, and within a short distance from 
each other. 

I once knew the wells of a whole village to be rendered 
unwholesome by the rotting of hemp in the ditch which sep- 
arated the dwellings from the public walk. As the state of 
the wells was attributed to some want of care, I was request- 
ed, by public authority, to ascertain the true cause of it, and 
found it to be occasioned by the filtration of the water of the 
ditch into the wells. I caused the ditch and the wells to be 
thoroughly drained three times, and the water was thus re- 
stored to purity. 

I have often observed that the use of wells was necessari- 
ly discontinued on account of the proximity of a sheep-fold, 
a stable, or a ditch for manure ; the filtrations from them 
and from the substances decomposing in their neighbourhood 
rendering the water totally unfit for use. To preserve the 
water of wells pure, it is therefore necessary, that no animal 
or vegetable substance which can be decomposed, be depos- 
ited near them. 



$72 CHYMISTUY APPIIF.I) TO AGRICULTURE. 

Wlien the w.-itrr of wolls is supplied by living streams, or 
M'licn tiic ground around tlieni is pavctl, or coni^istw of beds 
of Htonc or hard clay which will not allow tlic water to fil- 
trate through, the precautions which J have suggested arc 
not so absolutely necessary ; but these circumstances rarely 
occur in the country. 

Cistern-water would be purer and more wholesome than 
any other, if the roofs, eavc-troughs, and basins, could be 
kept j)erfectly clean ; l)ut the tilth dej)osite(i by pigeons 
and other birds u\k>u the roofs, is carried by the rain into 
the reservoir, and renders it disagreeable to drink, though 
it is not absolutely unwholesome : this I have observed to 
be the case U]>on the most elevated table lands of our moun- 
tains, where the inhabitants have no other resource for 
procuring the water necessary for domestic purj)Oses. 1 
have also observed, when care was taken to cleanse the 
troughs and reservoirs fre(iuently, and to conduct the first 
portions of the rains into pools, lor the use of the animals, 
80 as to receive only that portion which fell uj)on the roofs, 
after they had been well washed, that this water could be 
kept throughout the year, and that it furnished a drink 
equally healthy and agreeable. 

In most districts, the water of pools forms the only re- 
Fource for supplying the wants of animals ; and when these 
become dry, during the summer, the animals must often be 
driven a considerable distance to procure necessary drink. 
In order, therefore, to prevent the water of |X)ols from filtrat- 
ing into the ground, and likewise to preserve it sweet, the 
bottoms of jX)ols should be paved. 

In spite, however, of all the precautions which can be 
taken, it is almost imj)ossible to preserve the water in |K)oIs 
from deterioration : the excrements of animals, and the 
dirt from their feet, as well as the plants which always 
spring up in stagnant water, very soon change its color 
and its nature; it becomes green and thick, and to man, 
disgusting : fortunately, animals are less delicate, and 
can accommodate their inclinations very well to drink of 
this kind : it is even said, that when accustomed to it, they 
prefer it to the purest and most limpid stream. Such wa- 
ter rarely produces any bad eftect ; the filth which is mixed 
■with it is slow in decaying, and the ])lants which ."spring 
up, contribute to its healthfulness, and thus we rarely per- 
ceive from them that fetid odor which indicates putrefac- 
tion. The greatest fault in pond-water, is its temperature 



MEANS OF PREPARING WHOLESOME DRINKS. 273 

iii summer, when, from the contact of the atmosphere, it be- 
comes too warm to be an agreeable drink. 

It is difficult for country people to go out of their accus- 
tomed circle ; they employ themselves but little in improv- 
ing their food, or drink, but take such as nature yields ; 
their drink, however, may, with but little expense, and 
without much care, be rendered more wholesome and 
agreeable. 

The water made use of is often muddy, or has a bad 
smell, either of which faults may be corrected, by filtering it 
through charcoal : the process may be performed in the fol- 
lowing manner. Place a large cask upright in the coolest 
situation you can command, knock out the head, and form, 
in the bottom of it, a bed of clean sand, upon which place 
one of charcoal, and above these, fasten securely a double 
head pierced with holes ; when this is done, the cask may be 
immediately filled with the water which is to be purified : the 
filtrated fluid may be drawn off by means of a stop-cock, 
placed at the bottom of the bed of sand : it will be found 
to have become clear and inodorous in its passage through 
the sand and charcoal. The preservation of this apparatus 
requires but little care : when the charcoal ceases to produce 
the desired effect, it must be either well washed or replaced 
by a new portion. 

When a person Is laboring in the fields in summer, 
the use of warm water as drink, causes him to perspire 
profusely, by which his strength is reduced. Cold water 
might always be procured by the use of porous earthen 
vessels, the surfaces of which would be constantly mois- 
tened by the transudation of the fluid through their sides : 
the continual evaporation produced by the action of the sun's 
rays upon these vessels, serves to keep the water within 
them cool. It is by putting, water into their alcarasas, 
which they expose to the sun and to currents of air, that the 
Spaniards contrive to have cool water even in their hottest 
weather. 

Good water is undoubtedly the most wholesome drink; 
but man has almost everywhere contracted the habit of 
using fermented liquors, and this habit has created in him 
a want of them ; so that if he be deprived of their use, he 
loses his strength and energy, and becomes less able to 
work. 

The best fermented drink is wine, but excepting in the 
wine countries, where the low price of ordinary wine ren- 



274 CHYMISTRY APPLIED TO AGRICULTUIlK. 

ders the use of it common, the laborer has seldom the means 
of procurint^ it daily : it is therefore necessary that its place 
should elsewliere be suj)plied by such other litjuors as will 
produce nearly the same eliect, and this is done by the fer- 
mentation of (grains, fruits, milk, the sap of trees, &c., from 
the product of which there is formed in Euroj)e a great va- 
riety of liquors; some of these have become very important 
articles of consumption and of commerce. 

The peasants in the greater part of our districts, have ac- 
quired the habit of preparing their liquors from the fermen- 
tation of most of these substances ; and as the only object I 
have in view is to furnish information in regard to extending 
and perfecting these processes, I shall confine myself to 
pointing out such methods as are easily executed, and which 
require the emplojTnent of such substances only, as are 
everywhere in the hands of the agriculturist. 

All mucilaginous fruits, all fleshy stone fruits, excepting 
those which yield oil, all grains which contain gluten, sugar, 
or starch, are capable of undergoing the spirituous or alco- 
holic fermentation. 

The expressed juice of saccharine fruits may be made 
to ferment by exi^osure to a suflicicnt degree of heat. The 
method most commonly pursued, is that of crushing or 
grinding the fruits, and thus fermenting the pulp with the 
juice; HI this majijicr are treated apples, puar:?, grapes, 
cherries, &l,c. 6lc. 

For such fruits as are not very juicy, but contain how- 
ever some sugar and mucilage, and for such as can be 
made to keep better by being dried, some water is em- 
ployed to mix and dissolve the fermentable principles : in 
this class of fruits may be placed those of the service-tree, 
the cornelian cherry, the medlar, the mulberry, the privet, 
the juniper, the Neapolitan medlar, the thorn-ajiple, the 
wild plum, &c., and with them the dried fruits of the plum 
and fiir-treo, and of some of the other trees and shrubs be- 
fore mentioned. 

To produce the developement of the saccharine princi- 
ple in bread corns by germination, tli«'V miist be moistened 
with water : the spirituous frrriientation is afterwards ex- 
cited in them by immersing them in water, containing the 
yeast of beer, or leaven made of wheat flour. H^he opera- 
tion of germination may even bo suj)prt'ssed by mixing 
the meal with a jxjrtion of leaven and of luke-warm water ; 
this dough may be allowed to ferment for twenty-four hours, 



MEANS OP PREPARING WHOLESOME DRINKS. f^TS 

&nd may then be gradually diluted with water ; fermentation 
will take place in a few hours, and will go on regularly dur- 
ing two or three days. 

As directions for the manufacture of cider, perry, and 
beer, for general consumption, are much less necessary here, 
than those for procuring for farmers wholesome liquors at 
a trifling expense, I shall confine my observations to this 
object. 

Grapes furnish the best liquor, and that in the greatest 
quantity ; but when this is drunk clear, it serves but little 
purpose for quenching thirst ; when made use of in large 
quantities, it impairs the strength. The liquor called pi- 
quette^ which is manufactured by our farmers, supplies ad- 
vantageously the place of wine, serving as a tonic, and at the 
same time quenching thirst. 

Piquette is made from the pressed and fermented mash of 
red grapes, by means of water filtrated through it till it ac- 
quires, in some degree, the color and appearance of wine : 
it is, even in this state, a better drink than water, inasmuch 
as it is slightly tonic ; its good qualities may however be 
much increased by fermentation, 

Piquette can be kept but a short time unchanged, and 
from this tendency to sour, it is necessary that it should be 
made only in such quantities as are immediately wanted, and 
that the manufacture of it should be continued at intervals 
throughout the year. For this purpose the pressed mash of 
red grapes is put into a cask, care being taken to crowd it 
in till the cask is completely full, after which it is hermeti- 
cally closed so as to exclude air and moisture, and set in a 
cool, dry place. 

When the piquette is to be prepared for use, the head is 
taken out of the cask, and water is thrown upon the mash 
till the whole mass is moistened with it, and the water 
stands upon the top : fermentation soon takes place, as be- 
comes evident by the light foam which arises ; it is com- 
pleted at the end of the fourth or fifth day ; from this time 
the liquor may be drawn off for daily use, the place of the 
portion removed being supplied by an equal quantity of wa- 
ter thrown in upon the top of the mash. In this manner a 
cask of mash of the capacity of 66 gallons may furnish 
about 4 gallons of drink per day, and will continue to yield 
it for about twenty days. 

As the mash of white grapes cannot be made to ferment 
with the juice, this last is separated and put into casks tcfc 



376 CIIYMISTRY APPLIED TO AGRICULTURE. 

fernioiit by itself, and i\\fi piqiuttr is then made by adding iX) 
tlu; niasli tlio necessary (quantity of water. This licjuor i» 
more spirituous than that made from red grapes, and keeps 
better ; it is tlierefore reserved for use during the latter part 
of the sunnner. 

If instead of throwing pure water upon the mash, as is 
everywhere done, this liquid should first be slightly sweet- 
ened and heated, and then receive the addition of a little 
yvrisi, pi(/uitti of a very suj)erior quality would be obtained. 
In tjje absence of yeast or leaven, the scum which arises 
upon wine, especially white wine, during fermentation, may 
be used for the same [)urpose ; this foam or scum may be 
dried, and thus preserved for use without undergoing any 
change. 

Well-made j/iqurttc is a very wholesome drink for country 
people, from its tonic properties, as well as its power of 
quenching thirst ; it is far preferable, as a daily drink, to 
wine : but this resource is oidy local, as in those countries 
that are most fruitful in grapes, if the harvest fall short, there 
can be but \\ii\c jjujuctte made; it is necessary then to be 
able to sup])ly its place from some other source, and this is 
done by the fermentation of certain fruits. 

Apples and pears, as being the fruits that are most abun- 
dantly produced, are the most valuable for the purpose of 
manufacturing liquors ; a mixture of the two produces a 
more wholesome article of drink than does either treated 
separately. The juice of plums and of other wild fruits may 
likewise be added, as their a.stringency renders the liquor more 
tonic. 

E.xcellent licjuor may generally be produced both from ap- 
ples and pears, by following the well-known method of mak- 
ing cider, which consists in grinding the fruit with a mill- 
stone and fermenting the pulp and juice together : but irpon 
farms, where we seldom find the means of preserving 
liquors unchanged, it is necessary that the j)rocesses be sim- 
ple, and such as can be made use of for preparing them as 
they are needed ; I shall therefore recommend the following 
method. 

JJcgin to collect the apples and pears which fall from the 
trees towards the end of August, and continue to do so 
till they have arrived at maturity ; cut them in pieces as 
fast as they are gathered, and dry them first in the sun, 
and afterwards in an oven from which the bread has been 
drawn. If the fruit be well dried in this manner, though 



MEANS OP PREPARING WHOLESOME DRINKS. 277 

it may grow dark-colored, it may be kept unchanged for sev- 
eral years. 

When drink is to be prepared from these dried fruits, put 
about 60 pounds of them into a cask which will contain 66 
gallons, fill the cask with water and allow it to remain four 
or five days, after which draw off the fermented liquor for 
use. 

The liquor thus procured is very agreeable to the taste ; 
when put into bottles, it ferments so as to throw out the 
corks, as frothing Champagne wine does. Though whole- 
some and agreeable, it may become still more conducive 
to health by mixing with the apples and pears 2V ^^ ^he 
dried berries of the service-tree, and ^ij of juniper berries ; 
from these the liquor acquires a slightly bitter taste, and 
the flavor of the juniper berries, which is very refreshing, 
and it is besides rendered tonic and anti-putrescent. The 
use of this drink is one of the surest means that can be 
taken by the husbandman for preserving himself from those 
diseases to which he is liable in autumn, and for the attacks 
of which he is preparing the way during the greatest heats 
of summer. 

After the spirituous portions of the liquor have been 
drawn off, very agreeable piquette may be made from the 
pulp which remains in the cask ; for this purpose it is only 
necessary to crush the fruit, which is already soft, and to add 
to it as much luke-warm water, to which a small quantity of 
yeast has been added, as will fill the cask : fermentation 
commences in a short time, and is terminated in three or 
four days. To flavor this liquor and render it slightly tonic, 
there may be added to it before fermentation, a handful of 
vervain, three or four pounds of elder berries and of juniper 
berries. 

Cherries, and particularly the small bitter cherries, when 
ground and afterwards fermented in a cask in the same 
manner as the must of grapes, and then pressed to sep- 
arate the juice from the pulp, furnish a liquor contain- 
ing much spirit. The wine made from cherries, when dis- 
tilled, affords an excellent liquor, which although not ex- 
actly the same as the good kirschivasser of the Black Forest, 
is yet a valuable drink, and is sold in commerce under the 
same name.* 



* I know an intelligent landholder, who, without any interruption 
to his other agricultural occupations, makes every year two or three 
24 



278 CHVMISTRY APPLIED TO AGRICULTURE. 

Tho berries of the service-tree dried in an oven and put 
into a cask, in tlie j>r<ijK>rti<>n of alxmt 1<> or IH }M)unds of 
fruit to '2(U gallons of water, furnish, after four or live days' 
forniontation, a very good drink. Pkinis and figs dried, 
eitlicr hy the sun or in an oven, may be nia(ie use of for the 
iame purpose. 

In order to render tlie liquor more wholesome or more 
aorreeable, several kinds niav be mixed toaether, and thus 
the defects of one kind will be compensated ibr by the good 
qualities of another : a few handfuls of the red fruit of the 
bird-catcher's service-tree counteract the flat, sweetish taste 
of certain other fruits. 

In our farn^ing districts the berries of the juniper are care- 
fully collected and fermented, in the projx)rtion of about 30 
lbs. of berries to I5H^ gallons of water: the drink procured 
from these is one of the most wholesome possible, but it re- 
quires a little use to reconcile one to the odor and flavor of 
it; those, however, who do drink it, ])refer it, after a short 
time, to any other liquor.* 

The use of juniper contributes so much to health, that I 
cannot too strongly recommend its being mixed in greater or 
less quantities with all fruits which are to be subjected to 
fermentation : its flavor alone will disguise the taste of such 
li(piors as, without being unwholesome, are flat, sickish, or 
otherwise unpleasant. The rinds of oranges or lemons, aro- 
matic plants, angelica roots, peach leaves, &,c. may likewise 
be mixed with any of those fruits which are naturaJIv too 
sweet, and thus serve to raise the flavor of the fermented 
liquor, and render it more strengthening and eflicacious in 
preventing the attack of disease. 

That j)art of CEiujIogyt of which I treat at this tijne, is 
still in its infancy, but I do not doubt that by the applica- 
tion of the true principles of science, and by emj>loying 
cnily those j)ro(lucts which nature vields us abundantly and 
without expense, we can procure for the husbandman a 

thousand francs' worth of this liquor : the peasants brinj» their cherries 
to him, and he returns them one half of the j)roduct of tne distillation. 

• The fruit of the struwherrv-tn'e, iiuullar, plum, Neapolitan med- 
lar, thorn-applf, cornt'lian clirrry, privet. tVc. may be treated in the 
same inaiuicr, but the litjuor made from tlu-m is not worth so nnirh as 
that madi- from tiic fruit*! above mentioned ; it is used only by the 
poorest cla«8 of peasants. 

[ I (Enolo^y, (vnoloir'ie French, from 0^10?, irinr, and /./--/oc, account 
of Science or knowledge of making wine. — Tr.J 



MfiANS OF PREPARING WHOLESOME DRINKS. 279 

Variety of drinks more healthy, more agreeable, and better 
adapted for quenching thirst, than the weak and imperfectly 
fermented wines made from green grapes. 

I have limited myself in this work to pointing out the 
simplest methods in which such articles as are within the 
reach of every peasant may be made use of; if such 
liquors as are more spirituous be wished for, they can be 
procured by dissolving from 4 to 6 lbs. of the coarsest kind 
of sugar, in from 5| to 10^- gallons of warm water, and 
throwing the solution upon the mash when the cask is filled 
with it.* To this may be added any number of pounds of 
raisins. 

Liquors suitable for drinking may likewise be manufac- 
tured from the sap of several kinds of trees. In Germany, 
Holland, and some parts of Russia, as soon as the returning 
warmth of spring begins to cause the ascent of the sap, holes 
two or three inches deep are bored with a gimlet in the 
trunks of the birch trees ; through the straws which are in- 
troduced into the grimlet holes there flows out a clear, sweet 
juice, which, after having been fermented for a few days, be- 
comes a sprightly liquor, that is drunk by the inhabitants of 
those countries with much pleasure ; it is thought by them 
to be ver}' serviceable in counteracting affections of the kid- 
neys, stomach, &c. A single tree will furnish a quantity of 
drink sufficient to last three or four persons a week. The 
natives of the Coromandel coast fabricate their calou from 
the sap of the cocoa-nut tree. The savages of America 
prepare their chica from the juice of the maize ; and the 
drink of the negroes of Congo is made from the juice of the 
palm-tree. 

It cannot be doubted that the sap of all those trees which 
afford a saccharine substance can be made to yield a spirit- 
uous liquor, but T mention only these few as instances, be- 
cause our own wants may be abundantly supplied from our 
fruits and grains. 

The fermentation of rye and barley has afforded from 
time immemorial a liquor, which has supplied the place of 
wine for the use of the common people in nearly all those 
countries in which the vine cannot be made to flourish : 
in those where wine is made abundantly, the use of beer is 
still very extensive, both on account of the nutritive quali- 
ty which it possesses in a high degree, and its power of 
quenching thirst. Though beer may be brewed upon so 

* Supposing the cask to contain 66 gallons. 



2S0 CMYMlSTRY APrLlKI) TO AtiRICULTt'RC. 

small a scale as to sii|)j)ly tlio wants of a siiifrlo familv, I shall 
eiit<'r into no explaiialion of tlio procrss, as it rccjiiircs a de- 
gree of care not usually to be found amongst the peasantry, 
and utensils which they do not possess : I shall confine niy- 
peif to jK)intin<r out some processes by means of which^ 
thoufrji they are simple and imperfect, some very wholesome 
drinks may be obtained from (grains. 

The sole drink of the common i)eople, and one which is 
not disdained even by the richest proprietors throughout 
the vast extent of the Russian territory, is qiioss, and it 
is there retrarded as being nourishing and healthy. We 
are informed by M. Percy, Surgeon-General of our armies, 
that tin; French soldiers who had been accustomed to 
drinking wine and beer, frit at first some repugnance 
towards the use of qiiass, but they very soon became ac- 
customed to it, and in the end loved it so much as to man- 
ufacture it themselves ; they found that it gave them 
FtreuiTth and flesh, and preserved them from the attacks of 
epidemics. 

In manufacturing quass, one tenth j)art of the rye to be 
emploved is steepi^d in water till it becomes soft, it is then 
spread thiidy upon planks in a place warm enough to pro- 
duce germination, and it is there sprinkled occasionally with 
warm water. The remainder of tlie rye, after having been 
grotmd, is mixed with the germinated grain, and the whole 
is diluted with two gallons and a half of boiling water ; the 
vessel is then set into an oven, from which bread has just 
been drawn, or ex|)osed to an ecjuivalent degree of heat, 
during twenty-four or thirty hours: if the vessel be put into 
an oven wliirli it is necessary to heat everv day, it may be 
removed diiriuix bakinjx, and returned acrain after the bread 
is taken out. After this first operation the fermented sub- 
stance is diluted by mixing with it 2^ gallons of water at the 
tenijx'rature of 1*2' or \i)° ;* this mixture is stirred for half 
an hour and then allowed to settle. 

As soon as a de|)osit is formed and the liquor becomes 
clear, it is thrown into a cask where fermentation takes 
place; this is com|)lete(l in a few days, when the cask is 
removed into a cellar, and the f/itnss soon becomes clear. 
It is in this state that r/i/ass is drunk by the Russian peas- 
ant ; but it is nnich improved by being drawn off into jugs 



[•No scale is fr'won ; if of the cpntierado, equal to from 53° to 59" ; 
if of Reaumur, to from .7.) to t)5 . — Tu] 



MEANS OF PREPARING WHOLESOME DRINKS. ^1 

as soon as it has formed its deposit in the cask, and bottled 
after having been preserved in these vessels till it has become 
clear. 

Quass prepared in this manner has a vinous and sharp 
flavor which is not unpleasant. The color of it is not very 
precise, being of a yellowish white. 

The imperfections of quass might be easily remedied by 
adding wild apples, or pears, or juniper berries, to the fer- 
mented substances. The fermented liquor might be racked 
off several times from its lees, and clarified by the same pro- 
cess which we use for wine. 

The different deposits which are formed during the manu- 
facture of quass are entirely of malt, and afford a nourish- 
ing and fattening food for animals. 

I have found that the operation I have just described for 
procuring quass, might be simplified with the best results by 
putting the cask in a place of which the temperature was be- 
tween 18° and 22°.* 

I mixed the meal and malt with water at the tempera- 
ture of 25°, ( = 77° or 88|^° Fahr. according to the scale 
used, — Tr.) so as to form a porridge ; this I put the next 
day into a cask, and added water at a temperature of 20° 
or 22°, ( z= 68° or 71° Fahr. ;) the liquor was stirred by 
moving the cask as the water was turned in, so as to mix 
its contents thoroughly ; about one sixth of the capacity of 
the cask was left unoccupied. The cask was shaken once 
a day for three days, and after that was left undisturbed ; 
at the end of five or six days fermentation was ended, and 
nothing more remained to be done than to clarify the 
liquor according to some of the processes which I have de- 
scribed. 

In most of the countries of the north, a drink, which is 
highly valued by the common people, is prepared by sub- 
jecting certain roots to fermentation in unheaded casks, 
into which they are put, either whole or cut into pieces ; the 
most esteemed is procured from beet roots. These liquors 
are nutritive, wholesome, and quenching to thirst ; but 
their whitish color and acid taste will for a long time pre- 
vent the inhabitants of our fields from making use of them. 
In countries where wine, piquette, beer, cider, &/C. are 
manufactured and sold at a low price, it would not be 

[* No scale is given ; if upon the centigrade, between 64.4° and 
TLS"^; if upon Reaumur's, between 72^° and 81^". — Tr.] 
24* 



2S2 CHYMISTRY APPLIED TO AGRICLLTt'RE. 

worth wliile to introduce the use of a new kind of drink, 
unless it approached, in taste, those already in use, and 
could be made easily and at a trifling expense. It is for 
this reas(jn that 1 have sought to improve tlie li(iuor which 
is })rocured at a low rate from the various kinds of bread 
corn. 

I put into a vat one hundred weight of rye or barley, 
and jM)ur uj)on it a sullicient (juantity of water to cover it 
to the depth of three or four inches; after allowing it to re- 
main four or five hours, I stir it carefully, and by means of 
a shovel scrape the grain into tliat part of the vat which is 
opjKjsite to the opening formed in the lower part and closed 
with a tap. I then draw out the tap, and allow the water 
to flow oiF; and when the grain is well drained, I close the 
hole and throw into the vat fresh water enough to cover 
the grain ; after two or three days the grain becomes so 
swollen and softened, that it can be crushed by pressing it 
gently with the thumb and finger; I then draw off the 
water, and spread the wet grain U{X)n the pavement or upon 
planks to germinate ; at first it is thrown down in a heap, 
but when the mass has become heated, which is the case 
in twenty or four-and-twonty hours, according to the tem- 
perature, it is spread in beds of two or throe inches in 
thickness. 

Whilst these beds are heating, they must be constantly 
stirred ; and this operation is repeated every six hours, and 
oftener if heat is developed in the mass. 

The first ai)pearance of the radicle is generally perceiv- 
ed as soon as the second day, in the form of a wliite jx)int 
at one end of the kernel, and, a short time after, the plumule 
shows itself at the other extremity. This is the time for ar- 
resting germination ; and indeed it must be done sooner, if 
the radicle should become, as it sometimes does, more than 
a line or a line and a half in length, before the appearance 
of the plumule. 

The beds are spread very thin, and ol'ten stirred with a 
shovel, and, to destroy the germs, are formed either in a 
place exjMjsed to the rays of the sun, or in one which is suf- 
ficiently heated to produce the same effect. 

The malt thus prepared is thrown into a vat, and water, 
heated to the temperature of I0\ ( = 104° or U'^^ Fahr. 
according to the scale used, whether of the centigrade or 
Reaumur. — 'J'k.) is gradually added to it, the grain being 
stirred and scpieezed by the hands, as the water is poured 



FARM BUILDINGS. 283 

ift» This operation is continued till the temperature sinks to 
25°; (=: either 77° or 88° Fahr. — Tr.) when the malt is 
converted into a porridge or thin dough ; it is then covered 
over and allowed to remain half an hour. At the end of 
this time boiling water is poured upon the dough, which is 
carefully stirred till the heat falls to 50°, (= 122° or 144° 
Fahr.) The vat is now covered again and kept for three or 
four hours, afler which the covering is removed and the con- 
tents stirred till the heat descends to 20°, ( =i 68° or 77° 
Fahr.) when the specific gravity of the liquor should equal 
7° or 8° of the hydrometer. 

In this state a quantity of beer or flour yeast, proportion- 
ed to that of the grain employed, is mixed with warm water 
and turned into the vat, the stirring being still continued. 
The temperature of the place in which fermentation is car- 
ried on should be from 68° to 77° Fahr. Fermentation will 
be perceived in two hours after the addition of the leaven, 
and, if the first operations have been well conducted, it will 
be terminated in two or three days, when the vat must be 
covered over and the liquor left to settle and become clear : 
in two days' time it may be put into a cask, and afterwards 
treated like wine. 

This liquor is very wholesome ; its color is that of opal, 
and its taste slightly acid. It can be improved by having 
the mash of grapes, especially those of the white kinds, fer- 
mented in the vat with the grain. 



CHAPTER XVIII. 



OP FARM BUILDINGS, BOTH FOR MEN AND ANIMALS, AND THR 
MEANS OF MAKING THEM HEALTHY. 

The situation of the first habitations is determined by 
the vicinity of a river, the proximity of a fountain, or the 
fertility of a spot of ground. The industry of the inhab- 
itants of these dwellings, and the abundant supply of pro- 
visions produced by them, gradually increase their num- 
bers around the same point, and the population soon 
becomes divided into two classes, of which one is de- 
voted exclusively to the cultivation of the earth, and the 



284 CHYMISTRY APPLIED TO A<;llICULTllRE. 

Other is employed in manufacturing and fiirnisliing to the 
agricuhurist all the implements required in labor. 

Rural buildings should be constructed without any refer- 
ence to luxury : the perfection of them consists in furnish- 
ing a healthful abode to the peoj)le and animals of the farm, 
and in storing conveniently and safely the products of the 
various harvests. 

These two requisites in farm building are seldom found 
united : in one place, men and animals are crowded within 
damp and badly ventilated places, where they contract innu- 
merable disca.ses ; in another, the harvests are destitute of 
any protection against the ravages of animals, and the peas- 
ant .sees the fruit of all his labors devoured before his eyes, 
without being able to prevent it. 

I shall not enter into particulars in regard to the best 
method of constructing farm buildinffs : others have written 
upoFi this subject, ujx>n which, after all, it is iinpossible to be 
very precise, as the necessary arrangements must vary much 
in different localities, according to the kind of materials 
that can be procured, the kinds of animals with which a 
farm is stocked, the nature of the climate, the fortune of the 
inhabitants, &lc. 

The art of constructing and arranging the buildings upon 
a farm in a convenient manner is not the one up<:»n which 
rural proprietors most need instruction; but that which re- 
lates to the salubrity of situation and the means of turning 
an infected dwelling into a healthful habitation, outrht to fmd 
a place in this work : to knowledge of this kind the farmer 
is almost everywhere nearly a stranger. 

The choice of a suitable sjx)t for a farm-house is not so 
easy a thing as may at first be thought : buildings of this 
kind should always be placed as nearly as jwssible in the 
centre of the domain, in order to avoid loss of time and la- 
bor in the transportation of the products : the oversight of 
a farm can likewise be managed more easily by this ar- 
rangement. 

Indcpendeully of these considerations, the buildinirs should 
be situated ujkju the most heathful jiart of the farm, and 
where the soil is the least valuable ; where there is no stag- 
nant water, and where there is a ])lentitul su|)j)ly of pure wa- 
ter, both for drinking and other d<jmestic purjxjses. 

It is often very difficult to find a situation exactly right 
in all these respects, but the most iu)|K)rtnnt considera- 
tion, and the one to which all others should be sacrificed, 
is salubrity. 



FARM BUILDINGS* 285 

A farm-house which is built upon a damp soil, or in a nar- 
row spot overlooked by surrounding heights, is always un- 
healthy ; the exhalations which arise from such spots become 
stagnant, and the inhabitants are continually surrounded by 
a moist atmosphere loaded with animal emanations, and 
with those arising from all the substances which are liable 
to be decaying in the neighbourhood of a dwelling. The 
greater part of the maladies with which the inhabitants of 
the country are afflicted, are occasioned by the dampness of 
their habitations. 

When, from the nature of the land and other circumstan- 
ces, no dry and airy spot can be appropriated for the erection 
of the necessary buildings, the evil should be lessened as 
much as possible by attention to certain precautions and ar- 
rangements : in all such cases the house or houses designed 
to lodge the work-people should be built over a cellar, and 
all should be well aired by means of large doors, windows, 
and other openings. Nor are these precautions, though of 
ihe first consequence, all that is necessary ; there are others 
that it is indispensable to attend to constantly, in order to se- 
cure health ; amongst these is the digging of ditches to carry 
off stagnant water and dry the soil, and the transporting to 
a distance from the habitation, of all such substances as are 
susceptible of putrefaction. 

Constant dampness in a house is destructive not only to 
health, but to every thing employed in a household, such as 
provision, clothes, &.c. : this cause alone is often enough to 
ruin a family. 

Those who are so unfortunate as to be condemned to live 
in such places, should employ every means in their power to 
icounteract the evils arising from dampness ; they should not 
remain long, either day or night, in those parts of a building 
where fires are not constantly made ; it would even be use- 
ful to burn a little straw occasionally in the middle of the in- 
habited apartments, as this would serve to purify and change 
the air. 

The greatest degree of cleanliness should be observed in 
the interior of these habitations ; no substance which is lia- 
ble to be decomposed, should be allowed to remain in them ; 
the walls, planks, and furniture should be carefully rubbed 
to remove the dampness which they so easily imbibe. With 
such precautions the unhealthfulness of a house may be 
imuch lessened. 

The dwellings of animals become even more easily in- 



2S6 CIIYMISTRY APPLIED TO AGRICULTURE. 

fected tlian those of men, since no calculation is made as to 
the extent of gr(jMnd, or (juantity of air that should he allow- 
ed them, to admit of their hreathinjr freely, and to prevent 
their sutferin;^^ from Um great an accumulation of heat. Up- 
on most of our farms they are crowded into hadly aired caves, 
where their excrements are allowed to remain and rot 
throughout the year, forming a damp and hot atmosphere, 
and from th(!se infected dens they are not hrought out, es- 
pecially during the winter, excepting to drink. Is it then 
astonishing that the mortality amongst the animals of our 
farms should he so great ? 

Woolly animals do not fear the cold, and the shelter of a 
shed is sullicient for them in winter : in countries as cold as 
France and more damp, they are folded in pens nearly 
through the year. 

As cattle constitute the j)rincipal riches of a farm, their 
dwellings should be carefully attended to : the numerous dis- 
eases which they suffer from, and especially those that are 
contagious, and which jiot unfre(|uently destroy the whole 
live stock of a farm, most commonly arise from a neglect of 
the cleanliness necessary to health, in the stahles and sheep- 
folds. The emanations arisinj; on all sides from the bodies ol 
the animals, mix with the putrid exhalations arising from the 
decomjX)sing contents of their habitations, and the air is 
thus loaded with the elements of many maladies : this state 
of the atmosphere may be prevented by the use of the very 
simple and eificacious methods employed for rendering pris- 
ons and hospitals healthful abodes; the principal of these 
are «is follows. 

That the habitations of animals may be healthful, it is 
necessary that they be spacious enough not only to allow of 
free respiration, but to permit the inhabitants to assume all 
the j)ositions natural to them. It is likewise necessary that 
they should be well ventilated ; this may be done by means 
of windows or doors placed ujkiu opj)osite sides so as to form 
a thorough draught of air through ; in this way respirablo 
air will be constantly brought in, and the pernicious exhala- 
tions as constantly carried otf. 

It is likewise of great imj>ortance that the llfwjrs »)f these 
dwellings should be paved, and that a slight slope should be 
given to them, by which all ruiui<l matters mav be carried 
oir and conveyed into a reservoir : the j)avcment should be 
raised a little above the level of the ground uj)on the outside 
of the buildings. 



FARM BUILDINGS. 287 

The cribs should be occasionally scrubbed with weak lye, 
and once a year a coat of lime whitewash should be laid up- 
on the walls. 

When the floors of stables and sheep-folds are not paved, 
the bed of earth of which they are formed should be remov- 
ed several times in each year and carried into the fields, its 
place being supplied by a bed of rubbish from salt-petre 
lands, or by any other dry and porous substance. 

Those animals that are accustomed to feeding in the open 
fields, should not be unnecessarily confined in buildings, as 
they suffer from weariness, and from the impure air, if de- 
tained too long in them. There are but few days in the 
year when they may not be allowed to come out into the 
open air for several hours, since even our greatest degree of 
cold is not injurious to their health, and as soon as the build- 
ings are left vacant, the doors and windows should all be 
opened to allow of free ventilation. 

In some countries no use is made of litter for animals, 
and in others the litter employed is allowed to remain till 
it is almost entirely decayed ; both of these methods are 
wrong and contribute equally to render the abodes of ani- 
mals unwholesome. The litter used should be removed at 
least as often as once a month ; and in the intervals fresh 
layers should be added as soon as the others become foul 
upon the top. Where no litter is employed the danger of in- 
fection must be avoided by having the floors cleaned every 
day. 

Another and not less pernicious custom is that of forming 
dung-hills in the corners of stables and sheep-folds, instead 
of removing the clearings to some other place. By this 
method cleanliness is secured to a certain extent, but the 
danger of infection is not removed. 

When any contagious disease does make its appearance 
amongst the animals in the stables or sheep-folds, the first 
step to be taken is to separate the sick from the well, in or- 
der that they may be subjected to different treatment, and to 
remove the whole to some other spot. 

In order to restore the infected building to a state fit for 
being again inhabited, proceed as follows. 

After having removed all the litter, wash the pavement, 
if there be one, thoroughly ; if there be none, scrape the 
ground so as to remove from it whatever may have been 
made, by moisture, to penetrate into it. Burn sulphur in 
all the different parts of the enclosure, so that the vapor 



288 CHYMISTRY APPLIF.I) TO AiiRICULTURE. 

ninv poiK'tratc! into ovorv corner ; after which whitewash the 
Willis and cciliiii;fs witli lime, and at the end of several days 
the animals may return without danger. 

The vapor of chlorine (oxigenatcd muriatic acid) may 
be emj)I()ved f<ir fumigation instead of sulj)hur, it being 
more active than that: for thi.« puri)Ose, put into a vessel 
which can bear the fire, two ounces of fmely pulverized 
oxide of manganese, and pour U|)on it ten ounces of the 
rrniriafic acid of commerce ; set the vessel over a chafing- 
dish of burning charcoal, and a vapor of a greenish yellow 
color will soon appear upon the surface of its contents. 
This va|K)r, which is very siifTrKating, will s-pread through 
the whole enclosure and destroy all infection. To make the 
matter perfectly sure, place vessels of the same kind in the 
several parts of the enclosure, and thus kindle so many dis- 
infecting fires. 

Before the fumigation is begun, the outlets of the building 
must be carefidly closed, in order that the vapor, by being 
confined, may pro<luce its full effect. The j)er.^ons having 
the charge of the heaters must go out into the fresh air as 
soon as the vapor begins to affect their respiration. 

Animals that are crowded together in low, damp places that 
are not well lighted and aired, often become filthy, and then 
the moisture and the animal exhalations conspire to render 
the dwelling an unwholesome one. This evil mav be reme- 
died by either of the following methods. Place jwirtions of 
limestone in several vessels rai.sed a little from the ground ; 
the limestone will absorb moisture from the atmo.s[)here and 
likewise the carbonic acid given out bv the animals, and will 
consecjuently fall in pieces and ellloresce ; this air-slacked 
lime may be used for whitewashing and other pur[)Oses. Or, 
kindle a strong flame with straw or dry small wckhI, taking 
care to watch it well, and to remove the remain.s of the tire 
as it ceases to blaze; by this last means the whole internal 
atmosphere will be changed. 

I have emjiloycd each of these methods many times, and 
always with success. 



WASHING, BLfiACMlNd, &C» 239 

CHAPTER XIX. 

ON WASHING, BLEACHING, &;C. 

Nothing is unimportant to the interests of agriculture 
which tends to improve the method according to which the 
daily work of a farm is carried on : this consideration has 
induced me to treat here of the subject of bleaching. 

The object of bleaching is the removal of spots and stains 
from cloth : those that most frequently occur, are occasioned 
by oil, grease, or perspiration, and may be removed by soap, 
clay, or an alkali : those produced by the juices of certain 
fruits require different processes. 

Alkalies can be employed in cleansing fabrics of hemp, 
flax, or cotton ; only those of silk or woollen are destroyed, or 
at least injured by those substances. 

Before entering into the details of the bleaching process, 
I will mention one common practice which is very injurious 
to cloth. 

When household linen or articles of wearing apparel be- 
come soiled, they are usually thrown in a pile in some cor- 
ner of the dwelling, till a sufficient quantity is collected to 
form a washing : the consequence is, that the linen, being 
impregnated with animal moisture, even perhaps so as to be 
damp, heats and ferments, and the texture of it is thus more 
injured by lying, than by any use which is made of it as 
clothing. To obviate this evil, soiled clothing should be 
hung upon lines in a dry place, so that the articles may nei- 
ther be heated nor gather moisture. 

Washing should never be commenced excepting when 
the weather is such as to promise three or four fine days. 
Every housekeeper knows by experience that if she is sur- 
prised by rain before her washing is' dried, she will lose 
the greater part of her labor : besides, linen which is put 
away at all damp, mildews and decays, nor is any thing 
more injurious to health than the use of imperfectly dried 
clothing. 

If a bad state of the weather should prevent the linen, &c. 
from being dried in the open air, it should be hung in the 
barn or around a fire in the house, and not be put away in 
closets and drawers till thoroughly dry. 

The first operation in washing is that (5f soaking the 
linen : for this purpose, the several articles must be laid 
25 



290 CIIYMISTRY APPLIED TO AGRICULTURE. 

sinootlily in a tub, and covered over with a large coarse 
cloth, upon whicli water must be poured till the whole is 
covered with it. The day following a layer of ashes must 
be placed uj)on the coarse cloth, so as to be equally thick 
over the whole surface.* The water is drawn oif from the 
tub by njcans of a stop-cock j)laced at the lx)ttoni, and is 
tlirown into a boiler under whicli a fire is kindled : as 
soon as the water becomes hot, it is thrown upon the bed 
of ashes, and this oj)oration is repeated for some time: the 
ley thus formed being allowed to run out of the tub to sup- 
ply the place, in the boiler, of that which is thrown into 
the tub. 

In this way the linen gradually becomes hot and the ley 
acquires strength : when the liquid in the copper is near 
boiling, the operation is discontinued. The linen is allowed 
to remain in the tub till the ley has done running, after 
which it is carried to the wash-house. 

Nearly all fabrics of hemp re(juire to be bleached, rinsed, 
and dried, before being used; and as the expense of the 
soap required would be considerable, its place may be sup- 
plied by a soapy liquor that is much less costly : this sub- 
stitute is formed by putting a quantity of such soda as con- 
tains from yV(7 ^^ T^rnT o^ pure alkali, into an earthen jug, 
with twenty times its weight of water ; the jug must be 
shaken occasionally to hasten the solution, after which it 
will speedily become clear; this liquor has a slightly sa- 
line taste, and should mark 1° {=: specific gravity of 1.007) 
upon the hydrometer of Baume : when it is to be made 
use of, a (|uantity of olive oil f is put into an earthen ves- 
sel, and from thirty to forty times its weight of the alkaline 
solution is poured upon it : by the union of the two fluids 
there is immediately j)roduced a whit(^ licpior of a milky 
appearance, which, when shaken, froths like a solution of 
soap. This liquor is put into a bucket and diluted with a 
little hot water, and the linen is soaked in it, handled, ruh- 
!)ed, and turned, till it is j)erfectly clean. The ley and oil 

• In order to render the ley more artive, a little potash or soda is 
generally added tn the aslu's ; indeed some persons always mix a por- 
tion of lime with them, but, unless great care is us«^d, the texture of 
the cloth will be injured by it. 

t The coarsest kind of (dive oils, stich as are known in commerce 
under the names of fniiles dr fahrifjur, htiiles tie, triuturrs, and huiles 
d'nifiT, are those which should be employed for this purpose. The 
finer oils are not bo surtabk*, as they do not dissolve so well in the 
aolution of soda. 



WASHING, BLEACHING, ^C. 291 

need not be mixed, in any greater quantity than is required 
for use. 

When I introduced in the south the method of whitening 
cotton yarn by the steam from alkaline solutions, I presumed 
that the same might be used advantageously in washing and 
bleaching household linen, and experiment has confirmed my 
opinion. 

The apparatus I make use of in this process, is a boiler 2^ 
feet across at the opening and sixteen inches deep, and hav- 
ing a rim of 1 foot in width around the top : when the boil- 
er is fixed upon the fire-place, there is placed upon its rim, 
and at the distance of five or six inches from the opening, a 
tub three feet in diameter and four feet deep, but having no 
bottom ; the brick-work is raised all around the tub a foot 
from the level of the top of the boiler ; this brick- work is 
so closely united to the tub, that the steam can find no 
means of escaping. I have frames made five inches less in 
diameter than the tub, and consisting of cylindrical bars of 
wood fastened into solid borders at top and bottom, so as to 
leave spaces an inch wide between the bars : the bars across 
the bottom of the frame should be stronger than those of the 
sides. 

When this frame is set into the tub, there is an interval 
of two inches and a half between the two ; and the frame 
rests equally ujwn the border of the boiler, always leaving 
sufl[icient openings through which the steam can circulate. 

When this apparatus is made use of, the linen is soaked 
in a tub containing a solution of soda marking 1° or 2° on 
the hydrometer, (= specific gravity of 1.007 to 1.014;) it is 
then arranged upon the frame, care being taken to place 
those pieces that are most soiled at the bottom and upon the 
sides. 

Three or four pipes made of white iron or copper, pierced 
with small holes through their length and curved at the end, 
are placed upon the bottom of the frame at equal distances : 
the linen must be so arranged upon the frame, that the pipes 
may be put in as far as the top of the curve, which ought not 
to be covered with the linen. 

As soon as the apparatus is thus prepared, the remainder 
of the ley, which has been made to boil, may be thrown 
over the linen ; the top of the tub must then be covered 
over with large coarse cloths, with boards laid upon them. 
Whilst these arrangements are in completion, the ley with 
which the linen is wetted drains off and flows into the 



2^^2 CIIVMISTRV APPLIKD TO AGRICULTURE. 

boiler ; ;is so<jn as it is seven or eiglit inches in depth, the 
fire may be kindled. 

The steam arisini; froiii tlie boiling lev spreads itself 
lhrou(rh the whole mass ol linen, j)cnelrating into all its fold- 
ings throncrh the openings in the metallic pipes, so that the 
whole will ind)il)e a hiirh dej/ree of heat. The boiling of the 
ley may be continued during three or four hours. 

It may be feared that the bottom of the boiler may be 
burned by being kej)t dry from the evaporation of the ley ; 
but there is no danifer of this, as almost the whole of the 
steam which arises is condensed and returns again into 
the boiler. If it be judged necessary to guard against the 
jx)ssibility of this evil, a copper j)ipe of an inch in diameter 
may be attached to the bottom of the boiler, and extended 
to the outside of the wall of the fire-place, and to this may 
be fitted a glass tube, by means of which the height of the 
licpior may always-be estimated. If by chance it should hap- 
pen that the evajwration is not sufiiciently compensated for 
by the (juantity of condensed lluid returned, tlie fire can be 
clieckecl, and a new quantity of boiling ley thrown into 
the tub. 

When the heat has subsided, — that is to say, in eight or 
ten hours after the fire has been extinguished, — the linen is 
taken out and carefully washed. 

In the year 1802, I had two Imndred pair of sheets, 
wliich were taken from the IIotel-Dieu, washed, and was 
assured by the sisters of I'llopital, that they were cleaner 
and better bleaclied than by the ordinary process. The ex- 
pense of tlie washing, of which an exact account was kept, 
was less than three sevenths of the expense of the connnon 
method.* 

When articles made of very fine linen are to be steamed, 
a .'Jolulion of soap should be used in preference to one of an 
alkali. 

Cotton yarn can be bleached entirely by tlie above process. 
If it should haj)pen that any j)ortion be le.'is white than the 
rest, a few days' exposure in a field will render it perfectly 
white. 

Messrs. Cadet-de-Vaux and Cnraudau have exerted 
themselves nmch in im|)roving this j)rocess, and still more 
in causing it to be used, both on account of its simplicity 

• Thin appnrntiifl has born rstnblishod at the /?«rriVrc drs Bons 
Jlommrs, in tli»> thread riiannla('tr)ry of tlic Messrs. Bawcns. Seo 
the ;tbth Vol. of the .'hinalcs dc i'himie, page 2i*l. 



WASHING, BLEACHING, <fec. 293 

and its economy. It is now employed in many households, 
and its advantaores are much extolled. 

The spots formed by all substances upon clothing, cannot 
be removed by the application of alkaline solutions. In such 
cases other agents must be employed. 

Cloths of silk or woollen cannot be bleached in the 
manner here described, as the use of the alkaline solution 
would weaken or destroy the fabric. It is very important 
to know the means of removing spots and grease from 
clothing of all kinds, and the methods to be used must de- 
pend upon the nature of the cloths and of the cause of the 
stain. 

The substances by which spots are principally produced 
are oil, grease, wax, sweat, ink, rust, the juices of red 
fruits, &c. Scarcely any of these substances, when drop- 
ped upon clothing, can be removed by washing alone, even 
in the hottest water ; but each one may be dissolved or 
evaporated by certain agents. As I write for the inhabit- 
ants of the fields, I shall speak only of the simplest of these 
agents. 

A spot of wax may be entirely removed so as to leave no 
mark, merely by bringing a heated iron so near it as to cause 
it to melt and evaporate. 

Spots produced by any fat substance may be removed by 
placing the cloth between two pieces of soft brown paper 
and applying a warm iron, such as is used for ironing, 
over the upper paper : the oil is liquified and absorbed by 
the paper. As the fixed oils are volatilized with more dif- 
ficulty, the operation of freeing cloth from spots produced 
by them, is completed by the application of such solvents 
as are suited to the purpose. The alkalies hold the first 
rank in the class of bodies by which the oils may be 
dissolved, as they unite with them and form soluble soaps; 
but the alkalies act upon the oils only when in a nearly 
caustic state, and for this reason the use of them is con- 
fined to a small number of fabrics, and certain other sub- 
stances, which, though less active, will nevertheless combine 
with oil, are preferred ; amongst these are soap, the white 
clayey earths, the gall of animals, the yolks of eggs, &c. ; 
these last substances are often mixed and formed into solid 
bodies designed for the sole purpose of removing grease from 
'garments. 

The volatile oils are likewise employed for the same 
purpose, and they are also used for giving an agreeable 
25* 



294 CHYMI8TIIY APPLIED TO AGRlCULTUHC. 

perfume to clothing. The vestimtntal essences are composed 
of these. 

S})ots occasioned by the juice of fruit may, when recent, 
be effaced by washinir in water; but, when of long standing, 
this is insuflicient, and sulphuric acid or chlorine (oxygenat- 
ed muriatic acid) is employed. Tlie last of these acids de- 
stroys colors, and should tlierefore be applied only to white 
fabrics : it is sometimes combined with an alkali, that it may 
preserve its properties longer ; in this state it is known by 
the name of Javelle water. Suli)huric acid acts nmch less 
upon colors, and is therefore preferred for such articles as 
are dyed or printed. 

The spots produced by the oxide of iron are more lasting 
than those occasioned by the oxide of any other metal. The 
rust of iron, and some of the combinations of this metal, as 
that which exists in writing-ink, when dejX)sited upon cloth, 
become fixed, and form a fast color. 

A faint spot of iron rust may be taken out by the apj)lica- 
tion of a weak acid ; sjx)ts of ink by sulphuric or muriatic 
acid much diluted ; but the best method is tliat of covering 
the spot with cream of tartar reduced to a fine powder and 
then moistening it with water: after having allowed the 
cream of tartar to remain some time, rub the cloth carefully 
and rinse it. When an iron-rust spot is of a deep reddish 
yellow color, these acids are not sufficiently strong, and re- 
course must be had to oxalic, which may be used in the 
same manner as the cream of tartar. The place of oxalic 
acid may be supplied by the salts of sorrel of commerce; 
but the action of the latter is less perfect. 



CHAPTER XX. 

ON TlIK CULTIVATION OF WOAI), AND THE EXTRACTION OF 
INDIGO FROM IT. 

I'ou two centuries Woad {Isatis tinrtoria) has been culti- 
vated in Europe. This j)Iant is biennial, and its hairy and 
branching stalk rises to the height of three feet. As it is 
not killed by frost, it affords excellent f(KKl for cattle during 
the winter. It has however been less cultivated for fodder 
than for yielding the only permanent blue color which was 
known before the seventeenth century. 



C«LflVAT?ION OP WOAD, &.€» 295 

The discovery of indigo has greatly checked the culti- 
vation of this plant, and it is now limited to a few localities, 
where it is used for forming that coloring preparation known 
under the name of coques de pastel. I am, however, much 
inclined to think that the cultivation of woad may be re- 
stored to its former state, and that it will form, sooner or 
iater, one of the most important branches of French agri- 
culture ; and this opinion has determined me to devote a 
•chapter of this work particularly to the subject, and I shall 
treat of it under three heads. 

1st. The cultivation of Woad. 

2d, The manufacture of the cakes from the leaves of the 
plant. 

3d. The extraction of Indigo from it. 



ARTICLE L 
On the Cultivation, of Woad, 

It appears that the isatis tinctoria may be made to 
Bourish everywhere excepting in moist lands ; corn-fields 
and ground which is prepared for cultivation are adapted 
to its growth ; a good crop may be procured upon alluvial 
soils, but strong soils are preferable, provided they are not 
too clayey. 

The ground in which the seed of the isatis is to be sown 
must be ploughed three times, not only that the ground 
may be thoroughly softened and divided, but that all the 
weeds which would injure the growth of the plant, and 
increase the expense of weeding, may be destroyed. The 
different ploughings should be performed at intervals of a 
month or three weeks from each other. In stroncr lands 
and those which are disposed to retain too much water, 
deeper furrows may be traced at certain spaces, so as to 
form small drains, by which the water that would injure 
the plant is drawn off. The nature of the manure which 
is employed in the culture of woad, exerts a powerful influ- 
ence, not only upon the vegetation of the plant, but upon 
the quantity and quality of its coloring principle. 

The manures which consist of well decomposed animal 
or vegetable substances are the best, and for this reason 



29(i CHYMISTRV APPLIED TO AuRlCl'LTt'RK. 

niglit soil, tlu' (lung of sheep and doves, the decayed frag- 
ments of wool and silk, and the chrysalises of the silk-worui, 
are jjrcferrcd to any other manures. 

Tiiose substances that act as stimulants to vegetation, 
Buch as lime, plaster, marine salt, jKjudrette, mortar-rul>- 
hisli, ashes, &c. favor the growth of the plant withoiit atVect- 
ing the coloring principle. 

When land has been dressed with barn-yard maimre, it 
may be made to yield a crop of grain or maize, and after- 
wards be sown with woad. 

The season for sowing the Isfifis varies much in ditferent 
parts of Europe. In Italy, Corsica, Tuscany, &lc. it is 
sown in the course of the month of November. As it does 
not receive injury from the cold, it grows during the winter, 
and in March is sutliciently stroTig to overcome the weeds 
which usually make their appearance at that season. From 
the circumstance of its growing through the winter, it may 
be rendered a very important article of nourishment for 
horned cattle. 

In the south of France, woad is sown in March, and in 
England in February. In certain other countries it is sown 
after the corn harvests ; but in this case, a season favorable 
to vegetation is required, and the j)ractice of sowing at that 
time can only be Ibllowed advantageously in those climates 
where rains are certain, so that the cultivator may be able to 
gather two or three harvests of leaves before winter. His 
fields of woad will aiford him pastures for his cattle during 
the frosts, and he is secure at the return of summer of an 
abundant harvest of leaves. 

The seed of the isdfis should be soaked in water previ- 
ously to sowing, as germination will be ha.stened by it. The 
seed is sown broadcast, in the same quantity as wheat, and 
harrowed in. 'J'lie blade shows itself at the end of ten or 
twelve days. As soon as the plants have thrown out five 
or six leaves, they must be carefully weeded, and this must 
be repeated several times before gathering the leaves. "^Fhe 
design of the weedingf is to remove all strange plants that 
may sj)ring up in the same soil, especially the roots of bas- 
tard woad, (bourdaigne), the mixture of which injures the 
cr»loring matter of the pure isatis ; and to thin the rows 
of stalks, that those remaining may have more room to 
grow. 

The isafis, like other plants, has its diseases and its 
enemies. The leaves are fre<iuently seen covered with 



PREPARATION OF WOAD CAKES, 297 

yellow spots, which turn brown and acquire the appear- 
ance of rust : this seems to be occasioned by the sudden 
changes which sometimes occur in the atmosphere ; the 
rays of a hot sun darting inmiediately upon plants after a 
mist or rain, often produces a rustiness of the leaves and 
stalks. 

It often happens, that, in consequence of a great degree 
of heat accompanied by drought, the plants are not fully 
developed ; the leaves acquire not more than one third 
of their usual size, yet exhibit all the other characteristics 
of perfect maturity ; the harvest however is lost, for if the 
leaves be cut in that imperfect state, the plants either perish 
or languish without yielding any product. 

The isatis is not exempt from the ravages of insects . 
there is one called the flea, which often destroys the first 
and second harvests of leaves ; another, known by the 
name of the louse, attacks the last leaves, but does less in- 
jury than the other, because the first harvests are the most 
important. The snail and the cabbage-worm likewise com- 
mit some depredations upon woad. 



ARTICLE IL 

Preparation of JVoad Cakes. 

The manufacturer of woad cakes should avoid cuttinor 
the leaves of the plant, till the period when they are richest 
in indigo; this substance is, to be sure, contained in the 
leaves of the isatis, during all the periods of its vegeta- 
tion ; but the coloring principle does not present itself at 
all times in the same quantity or of the same quality. In 
the young leaves the coloring principle is of a delicate 
blue, in those of a middle age the color is deeper, and in 
the ripe leaves it approaches to black. It has likewise 
been proved by observation, that the coloring principle is 
obtained from the young leaves with more difficulty than it 
is from those advanced towards maturity. 

It appears, then, that the most advantageous time for 
gathering the leaves of woad, is when they have acquired 
their full growth. But by what marks is this to be deter- 
m'lnedJ 



296 rilYMlSTRY APPLIED T(» AURICULTfRE. 

The manufacturers of woatl cakes govern tlieruselves 
upon this sul)ject according to tlieir own observations, and 
their modes of procedure vary more or less in ditferent 
countries. 

In England and Germany, the leaves are cut as soon as 
they begin to dr(K)p, and their bluish color to degenerate 
into a pale green. 

In Thuringia, the leaves are gathered when they begin 
to drooj), and to give out a strong, j)enetrating odor. 

In Tuscany, the time for cutting the leaves is judged 
of by the color which a leaf affords when pressed between 
two linen cloths. 

In the Roman states, the leaves are considered to be 
matured when they lose the intensity of their color, and 
begin to fade. 

In Piedmont, the leaves are gathered when they begin 
to fall. 

In the south, the leaves are considered as being mature, 
when they exhibit a violet shade u{)on their borders. 

We are indebted to M. Giobert, of Turin, for an ex- 
cellent treatise upon woad, in which he .states that, ac- 
cording to his observations, the (piantity of indigo con- 
tained in the leaves of the plant in the most favorable 
seasons, increases progressively from the eleventh lo the 
sixteenth day of their vegetation, after which time it re- 
mains stationary during four or five days, and then be- 
gins to decrea.se. The observations of M. Giobert have 
been confirmed in the south of France, at Bedford, and in 
nearly all Italy ; and from them mav therefore be deduced 
a general rule, by which the cutting of the leaves of woad 
may be governed, whenever the vegetation of the plant 
has been favored by the combined action of a good soil, 
a warm atmosj)here, and a suitable degree (jf moisture ; 
for without this the leaves will not have reached maturity 
in twelve or sixteen davs, and they should not ho gathered 
before approaching that state. 

The extraction of the indigo is uniforndy performed 
with more ease at an earlier j)eriod of vegetation, than 
when the leaves are perfectly inalure : the (juantitv of 
c<^)loring matter obtained is equally great, and the hue of 
it is handsomer. 

The leaves of the isafis are gathered by plucking them 
off with the hand, or by oitting the stalks with a knife 
or pair of scissors ; but whichever way is practised, caio 



PREPARATION OF WOAD CAKES, f299 

iftust be taken not to injure the stalks or tops of the plants ; 
the cuttings may be repeated once in six or eight days, so 
as not to allow time for the quality of the leaves to de- 
generate. A mixture of the leaves of strange plants, and 
of the bastard woad, with those of the isatis tinctoria, must 
be carefully avoided. 

The leaves, when gathered, are put into baskets and 
conveyed to the work-shop in which the manufacture of 
woad cakes is carried on : when they have begun to wither, 
they are ground between two mill-stones equally chan- 
nelled ; the bruised substance being frequently stirred with 
a shovel, and the grinding continued till the nerves of the 
leaves can no longer be perceived by the eye. All the 
juice which flows out during grinding, is carefully pre- 
served to moisten the paste with when it is fermenting. 

The paste is carried under a shsd, the ground of which 
is a little sloping, and paved with cemented stones, in 
which are little channels for conveying into a reservoir 
the juice which flows out. Under the highest part of the 
shed is formed a bed of the paste three or four feet in length ; 
to render this bed as compact as possible, it is beaten down 
with heavy pieces of wood. Fermentation commences in 
a short time, the mass swells and cracks, and there flows 
out from it a black liquor, which is conducted into the res- 
ervoir by the channels in the pavement. In some manu- 
factories, this liquor is allowed to run off" upon the ground 
without the shed ; but the odor which it diffuses in this 
case is very offensive. 

Whilst fermentation is going on, attention is paid to re- 
uniting the mass when it cracks, and to moistening it either 
with urine, or with the juice which flowed from it when 
between the mill-stones. 

After the paste has fermented well for three or four 
days, the mass is again beaten down, and this operation is 
renewed several times during the twenty or thirty days that 
the fermentation lasts ; the paste being in the intervals 
moistened with the juice, and the surface of it united. 

In a cold season, or when the leaves are poor and dry, 
fermentation will not be completed in a month ; in Italy 
they often allow four months for it, and sometimes the bed 
is not removed till the following spring. 

There is a kind of worm which often takes possession 
of these beds, and sometimes in such numbers as to de- 
vour all the indigo contained in them; in this case the 



300 nivMisTuv Ari'i.n.D to agriclltl're. 

ho(]^ fnnst ho tiiriiod over, and, if this he not suflicient, the 
wlioh* must he aixain jiround in llie null. 

After fermentation, the paste seldom apj>ears of a uni- 
form texture, and there will he found in it some remains of 
nerves which are visihie to the eye ; for this reason it 
is subjected to a second grinding, after wiiich it is ready 
to he made into cakes ; this is done hy fillincr round 
wooden moulds with it, or by forming loaves four or five 
inches in diameter, and eight or ten in height, and usually 
wri^rliing about three pounds and a quarter. In the south 
f)f France the moulds are usually much smaller, and the 
loaves of woad, known by the name of shcl/s, weigh but 
little more than one pound. These cakes should, when 
broken, appear of a violet color, and exhale a good odor. 

The cakes are placed upon hurdles, and carried to a dry 
and airy place to harden. 

In most countries the cakes arc sold in this state to the 
dyers, wlio make use of them either to heighten their 
woad dyes, or for dying by themselves a soft blue ; but in 
general they are made to undergo another process, by 
which they are improved ; this is called i-t fining. This 
last operation is, however, seldom performed by the manu- 
facturers, but by the dealers to whom they are sold in large 
quantities ; the reason of this is, that the j)rocess of refining 
can be j)erformed advantageously only on large masses, 
and the proprietor of the fields for cultivating woad has 
only the ])roduct of his liarvcst, and the conveniences ne- 
cessary for making it into cakes. 

For refining the woad cakes, it is necessary that they 
should either be ground in a mill or broken in pieces with 
an axe ; the fragments are made into beds about four feet 
high, and sprinkled either with water, or, what is prefera- 
ble, with the juice of the leav(>s ; brat is develojunl in a short 
time, and a violent fermentation takes place. At the end 
of six days, the bed is turncti, so as to bring the interior or 
under portion upon the top ; this is watered in the same 
manner, and, five or six days after, the bed is again made 
over with the same care. These operations are renewed 
at short intervals, till the mass, having ceased to ferment, 
becomes cohl ; in this state all the animal and vegetable 
portions, with the exception of the indigo, are decomjKDsed, 
and it is now sold to the dyers to the greatest advantage. 

The mode of making woad cakes here described, is un- 
doubtedly the most perfect one, but it is not everywhere 



PREPARATION OF WOAD CAKES. 301 

practised. At Genoa they do not refine them ; in the de- 
partment of Calvados, and upon the Rhine, they pile up 
the leaves without grinding them ; and they mould the 
cakes as soon as the division of the mass will allow of this 
operation. 

It is necessary to observe, that an immense variety in 
the quality of the cakes is produced, not only by the na- 
ture of the soil and climate, but also by the difference 
of seasons, and by the care bestowed upon the cultivation 
of the plant and the gathering of the leaves ; and from 
these circumstances arises the different estimation in 
which they are held in commerce, and consequently the 
various prices at which they are sold. The leaves of 
woad yield about ^ their weight of good cakes ; these, 
when used with indigo to form dyes for producing a 
permanent blue color, serve not only to facilitate fermenta- 
tion, but add the indigo which they contain, to that which is 
brought from India, and thus render the dye less expensive. 

The cakes, especially those that have been refined, 
contain alone a sufficient quantity of indigo to give to 
cloth all the shades of blue, which can be procured from 
the imported material. M. Giobert states, that M. Alex- 
ander Mazera, in the presence of several skilful dyers and 
manufacturers, and of the commissaries of the Academy 
of Turin, colored with the cakes four pieces of fine cloth 
of four different shades, and they were judged to be at 
least equal in brilliancy and durability to those obtained 
from the best Bengal indigo. 

M. de Puymaurin has published an account of a process 
by which the inhabitants of the island of Corfu color, with 
the leaves of the isatis, the woollen stuffs of which they 
make their clothing. The practice with them is to cut 
the leaves when the plant is in flower, and, after carefully 
drawing out all the nerves, to reduce them to paste in a 
mortar ; this paste is dried in the sun, and when it is to 
be used for coloring, is placed in a bucket and moistened 
with water ; the mixture gradually heats, and at length 
ferments strongly ; water and a little weak ley of ashes 
is added, and the paste undergoes the putrid fermentation. 
Into this composition the cloth which is to be colored is 
plunged, and allowed to remain eight days, turning it from 
time to time ; in this way it acquires a deep and lasting 
blue. The ease with which this process is executed, 
would render it very useful in farmers' families. 
26 



302 CilYMISTRY APPLIED TO AGRICULTURE. 

ARTICLE Til. 

The Extraction of Indigo from \Voa(l. 

Beforc the discovery of indigo, the isati^ tinctoria was 
cultivated for the nianufacture of woad cakes in nearly 
all parts of Hurope : the blue color obtained from this 
plant was the most durable one known, and the commerce 
in woad was immense. 

The neighbourhood of Toulouse, and particularly Lara- 
guais, furnished an enormous (juantity of woad, and the 
cakes pre})ared there were everywhere considered of the 
best quality : this section of the country became so rich, 
that it was called the pny:> dn cocngne, from the name of 
its manufacture ; and tliis epithet lias passed into a proverb, 
and is used to designate a very rich and fertile country. 

Two Innulred thousand packages of cakes were ex- 
ported every year by the port of Bordeaux alone : so great 
was the want of this connnodity amongst foreign nations, 
that, (luriuiT the wars we were obliged to sustain, it was 
always agreed that the commerce in it should be free and 
protected, and that foreign unarmed vessels should be 
allowed to come into our j)orts to obtain it. 

The finest establishments at Toulouse have been found- 
ed by the manufacturers of woad cakes ; when Charles V. 
wished to secure the ransom of Francis I., who was .1 
prisoner in Spain, he recjuired that the rich Beruni, a 
manufacturer of this article, should become surety for it. 

The indigo, which is an extract from a plant of the 
same name, first made its appearance in Europe early in 
the seventeenth century ; and the injury which the culti- 
vation of woad would receive from it, was foreseen from 
the first moment of its introduction. An ecpial weight 
of the pure coloring principle of indigo contains about 
\V)~> times more coloring matter than the woad cakes do.* 
Thus 15 lbs. of good indigo, such as is usually employed in 
dying, are ecpial, in point of coloring matter, to 'J(»"2r> lbs. 
of the woad cakes. From this, some judgment may be 
formed of the difliculty of producing a deep dye with the 
woad alone ; for, besides the inconvenience of managing 

• This ciilculation is foiindrd upon the supposition that 100 lbs. of 
woad leaves yield '.] oz. of indigo ; for the cakes, which contain all the 
inditrnof the plant, represent only ^ of the weight of leaves employed 
in their nianut'ucture. 



EXTRACTION OF INDIGO FROM WOAD. 303 

such an enormous mass of matter in a dye, the colorer 
must be very skilful in his art to draw from it a uniform 
and well-sustained color. It is not then astonishing, that 
the use of indigo should have superseded that of the cakes, 
and that consequently the culture of woad should be much 
diminished. 

Henry IV., who foresaw the depreciation of this princi- 
pal branch of French agriculture, wished to arrest the 
evil in its infancy, and by an edict of 1609, he pronounced 
the penalty of death against all those who should make 
use of " the false and pernicious drug calkd indigo.'"' 
The same severity was adopted by the governments of 
Holland, Germany, and England, though they had not the 
same interest in the subject : the law was, however, main- 
tained and executed only in the last of these kingdoms. 

This source of prosperity may easily be revived in 
France, not however by increasing the manufacture of 
woad cakes, of which we cannot extend the use, but by 
extractinor from the leaves of the woad, indiso which shall 
be equal to that brought from India. 

The long war of the revolution deprived us of naviga- 
tion, and our colonial supplies of various articles became 
consequ'^'itly very dear and incomplete: in this state of die- 
tress and privation, government made an appeal to our 
learned men, upon the subject of attempting to obtain 
from our own soil a portion of the supplies, which had 
before been brought hither from the New World. The 
efforts made were not unsuccessful, and in a short time 
indigo was made from woad, which was not excelled by the 
best of that brought from Guatimala. 

Three large establishments for the manufacture of this 
article, were established at the expense of government ; 
one at Albi, another in the neighbourhood of Turin, and a 
third in Tuscany. These establishments prospered for 
several years, and the processes for obtaining indigo were 
much improved in them ; but the changes which took 
place in 1813, deprived the manufactories of protection ; 
the establishments were sold by the respective govern- 
ments, and thus this profitable branch of industry, which 
would have continued if the establishments had belonged 
to individuals, has disappeared. M. Roques, a skilful 
dyer at Albi, has alone maintained an establishment that 
he had formed, and during ten years he has made use of 
no other indigo for coloring than that which he prepared 
himself from woad. 



304 CIIYMISTKY APPLir.D TO AGRICULTURE. 

At this time, nolliiiiir more is necessary than to make 
known those simj)ie and advantajjeous methods by winch 
this l)rancli of njaniifactiiring industry may l)e conducted. 
1 shall however observe, tliat it is more protitable to the 
proprietor to extract the indigo from woad, than to convert 
the le.ives of tlie plant into cakes. 

llellot assures us that it had been proved in his time, 
that four pounds of good Guatimala iudigo yielded as much 
coloring matter as a package of Albigense woad cakes 
weighing two hundred and ten pounds. 

At Quiers, in Piedmont, where the dyers are very skilful, 
it is calculated that three hundred pounds of the cakes 
artord as nujch coloring matter as six pounds of the best 
indigo.* 

According to the experiments of M. Giobert, there is no 
doubt that it is more protitabU; to extract indigo from the 
woad leaves, than it is to convert them into cakes. 

The indigo which is obtained in America from the anil, in 
ludostan from the nuricum, and in Europe from the isntis, 
does not dilfer sensibly in ciiaracter : the care which is 
taken in the manufacturing of it, and the state of the 
plants, which many circumstances may cause to vary dur- 
ing vegetation, can alone j)ro(luce some changes in its 
color, and cause its value in commerce to vary. 

This difference in the quality and price of indigo, may 
arise in some degree from the dilTerent methods adopted 
for extracting it. In America it is made to ferment cold ; 
in Java in the form of a decoction ; and generally in India, 
since the discoveries of the learned Roxburgh, by infusion. 

Prior to the year ISK), a great lunnber of processes had 
been employed in France, Germany, Italy, and England, 
for obtaining indigo from the isatis, without any general 
method having been established. It was at this period that 
the French government, urged by the necessity of obtaining 
a coloring substance which the state of the country would 
not allow them to import but at a great expense, formed 
establishments for the extraction of indigo from woad, and 
offered encouragement to those who would undertake the 
business. 

I shall Fiot describe all the methods that were practised 
during the three years following hSlO. i shall confme 

' Those results appear to nie exajrue rated. I place dependence 
only on those of the exix'riiiionts which have been made under ray 
own inspection. 



BXTRACTtON OP INDIGO PROM WOAB. 305 

myself to pointing out that which is the simplest, least 
expensive, and most expeditious ; and which the most 
constantly furnishes indigo of a uniform and good quality. 

No other apparatus is required in this process, than a 
boiler for heating water, one tub for leaching, a second for 
a receiver, and a bucket in which the water charged with 
indigo is beaten to precipitate the fecula. 

The manner of operating, as described by M. Giobert, 
author of the process, is as follows. 

Begin by heating the water till it boils. In the mean 
time, place the leaves of woad (which have been cut 
according to the signs of their fitness pointed out in the 
process for making woad cakes) in the tub, taking care to 
arrange them so that they shall not be anywhere crowded, 
and that the distribution shall be equal throughout the 
whole inside of the tub. Cover the tub with a hurdle of 
osiers, or with a coarse net, and throw over it a coarse 
woollen cloth. 

When the apparatus is thus arranged, pour boiling water 
over the leaves till every portion of them be moistened, and 
the water stand upon the top. Remove the woollen cloth 
and the net, and stir the leaves gently, that the water may be 
equally diffused through them, and may not descend to the 
bottom of the tub, where it will not act upon them. 

Allow the leaves to rest during five or six minutes, and 
then draw off the liquid through the stop-cock of the tub, 
causing it to pass through a sieve into the receiver. If the 
color of the liquid be too light, not having the depth of 
well-charged new white wine, the flow of it must be 
stopped, and that which has run out is to be again turned 
upon the leaves, and allowed to remain until it has acquired 
the appearance just mentioned. 

As soon as the liquor is drawn off, turn a fresh quantity 
of warm water over the leaves, and allow it to act upon 
them for the space of fifteen minutes. During this second 
infusion, remove the water of the first leaching into the 
bucket called the heater, and cause that of the second 
leaching to flow into it, thus mixing the two. 

As the leaves are not by these two leachings exhausted 
of all their indigo, cold water must now be turned upon 
them ; and this may remain an hour or two. The liquor 
of this third leaching is kept by itself, to be treated with 
lime-water. After it has been drawn off, the leaves may 
be strongly pressed, to obtain from them all the juice whick 
26* 



300 CHYMISTRY APPLIED TO AGRiCVLTVnt. 

may serve to derpcii dyvs, made of the cakes, for obtaiiiinj^ 
liiLjlit blues. M. Pariolati, dyer at Ciuiers, has loiiiid tliis an 
excellent article for giving a fine blue to silks. But it can be 
employed only wlieii the dye-house is in the neighbourhood 
of the indigo manufactory. 

The leaves may also be bruised after having had the two 
first waters passed through them, and be formed into cakes 
in the usual manner. Tiicse cakes will not be of the first 
quality, but they are useful as a fermentable substance, and 
produce in this way the same effect upon the woad dye 
which is prepared for coloring. This has been proved by 
experiments conducted upon a large scale, and these cakes 
are in demand at a price one third less than those made 
from leaves containinjj all the indigo. 

The process whicli I have described for obtaining indigo 
by a hot infusion, is more simple than any other mode- 
But as the indigo is more or less formed or oxidated in the 
leaves, according to tlie period of their vegetation, it is not 
at all times equally soluble, and especially when it is (as in 
leaves that have passed their maturity) in the state of black- 
ish blue. It is therefore necessary, when this process is to 
be followed, that the leaves should be gathered between the 
sixteenth and eighteenth day of tlieir growth, and before 
their borders l)ecoine shaded with l)lue, as, when that takes 
place, the indigo has arrived at a degree of oxidation which 
prevents it from being completely dissolved. 

If the method of obtaining indigo by fermentation be 
less advantageous than the one I have already described, 
it is capable of being employed upon leaves which have 
arrived at a higher degree of maturity, and I shall therefore 
give a short description of it ; and I feel the more inclined 
to do this, because in small manufactories this process is on 
some accounts preferable to the other. 

When indiao is to be obtained by fermentation, a tub is 
about three fourths filled with woad leaves, pressed down 
so that they shall remain immersed in the water, which is 
thrown over them of the temperature of 15° or 10° Reau- 
mur, (= (m^ to 08° Fahr.) The heat of the manufactory 
should be at the same degree. Fermentation Mill in a 
short time be evident by the appearance of bubbles, which 
rise and break uj)on the surface, l^liis should be termi- 
nated in eighteen hours. The period when it should be 
stopped, may be known by the color of the water being 
that of a yellow lime, and by the formation, upon the top, of 



EXTRACTION OP INDIGO FROM WOAD. 30T 

a thin, greenish, and iridescent pellicle. When in this 
state, the liquor is to be drawn off into the receiving tub, 
and changed from that into the beating* vessel. 

In both methods, it is necessary to precipitate the indigo 
which is held in solution or in suspension in the water ; 
and this operation, which is called beetling or beating, is 
needed to give to the indigo the blue color which belongs 
to it. 

There are two methods of beating which are practised, 
one being applicable to the liquor obtained by infusion, 
and the other to that procured by fermentation. I shall 
here describe both of them. 

As soon as the heat of the liquor, which has been passed 
through the leaves in the manner described in the first 
process, has fallen to between 120'° and 111° Fahrenheit, 
beating is commenced. The instrument employed for this 
purpose is a broom, or a handful of willow twigs from which 
the bark has been peeled. With this the liquor is forcibly 
agitated, the quickness of the motion being gradually 
lessened as the infusion cools. 

As soon as a white foam rises upon the top, beating is 
suspended, but is resumed again as soon as the foam sub- 
sides, and assumes a fine blue color. If the liquor is too hot, 
or has been too much beaten, the blue borders upon the 
violet ; otherwise it is the color of the sky. Beating is 
continued at intervals, allowing the foam to exhibit its 
color. When by rest it appears only of a pale blue, the 
beating is continued without any interruption. When the 
foam remains white, or changes to a reddish color, the 
operation draws to a close. 

By beating, the color of the water, which was that of 
white wine, becomes more and more brown. The beating 
is ended, when upon pouring the liquor into a glass vessel, it 
appears of a uniform brown. Should a tinge of bluish green 
be perceived near the sides of the glass, the beating must be 
continued. Upon the whole, it is better to beat it too much 
than too little. The time requisite for performing the 
operation upon the liquor drawn from three hundred pounds 
of leaves, is generally about an hour and a half 

When the liquor is at length left undisturbed, the indigo 
is deposited in grains at the bottom of the bucket. Eight 
or ten hours are sufficient for this purpose. The liquor is 
then to be drawn off and the indigo dried, in order that all 
the water which could cause it to ferment may be separat- 
ed from it. 



30S ClIVMISTRY AFI'Lini) TO AtiRICULTURE. 

In tliis operation, no foreign substance by wliicli the 
indigo can l>e adulterated is employed ; and it is tberefore 
obtained as j)ure as the best of the inii>orted kind. 

When the leaves of the isatis are oi)erated upon with 
cold water by maceration, fermentation, or any other 
njethod, the indigo cannot possibly l)e separated by beating. 
The reason of this is, that the elevation of the tempe- 
rature is not high enough to cause the combination of 
oxvgen with tlie indigo, and thus to give it the color and 
other characteristics wiiich render it so valuable in the art 
of dyeing. 

The substance which in these cases is most usually 
employed to produce precipitation, is lime-water; but as 
this process requires much attention, I shall descril>e par- 
ticularly the use and action of this ingredient, that the man- 
ufacturer may be the better able to direct it. 

Atler all the water which has been prepared in the course 
of the day, has been collected in a tub, the operation of 
precipitating the indigo from it is commenced in the fol- 
lowing manner. 

The liquor is beaten almost uninterruptedly, and without 
any particular method, for half an hour, the operation being 
interrupted only to allow the foam to subside and exiiibit 
its color. When the liquor begins to appear of a deep 
brown, five or six pints of lime-water are thrown into it. 
The beatinor is continued, and the lime-water added at inter- 
vals, till the liipior exhibits a greenish yellow, begins to grow 
turbid, and to show in a state of suspension the substance 
which is alxjut to be ])recipitated. The (juantity of lime- 
water which is necessary to be used in this process, when 
added at intervals, in the manner here directed, is never 
fnore than one tenth of the volume of the li(]uor with which 
it is mixed ; but if the lime-water be all thrown in at once, 
the lime more than saturates the carbonic acid of the liquor, 
and tlie carbonate thus formed, being precipitated, niixet? 
with and weakens the indigo. 

In the last described method of pro<hicing precipitation, 
a large (juantity of air is introduced into the liquor by 
beating. This combines with the indigo, rendering it 
inK)luble in water, and forming at the same time a great 
deal of carbonic acid. The admixture of a small quantity 
of lime-wat<^r after each beating, j)roduces an acidulated 
carbonate, which remains in solution in the liquor, and a 
kind of soapy combination with the extractive and vegeto- 



EXTRACTION OP INDIGO FROM WOAD. 309 

animal portions of the plant, so that the indigo disengaged 
from its several combinations can be oxidated and precipi- 
tated more easily, and in a state of greater purity. 

The first result of this process appears to be a much 
smaller quantity of indigo than is obtained by employing a 
volume of lime-water equal to that of the liquor. But the 
indigo obtained is purer, being equal in quality to the kind 
which bears the highest price in commerce. This process 
may be employed in all cases ; even when the infusion of 
leaves is at 122° Fahr. The length of time during which 
beating must be continued in those cases in which it can 
alone be employed, is much diminished ; and yet the indigo 
obtained is equally as pure. 

When all the indigo has been precipitated, the water is 
drawn off. The precipitated fecula requires some further 
operations to bring it to the requisite degree of perfection. 

The precipitated indigo still contains a greater or less 
portion of particles which are not sufficiently oxidated, and 
consequently it has neither the color nor properties which 
characterize gpod indigo. Prolonged beating would, it is 
true, bring these portions to the desired state ; but it would 
likewise cause those particles which had been first oxida- 
ted to imbibe an additional quantity of oxygen, by which 
their color would be too much deepened, and indigo of 
this quality would be rejected in commerce as burnt ; it 
is therefore better to give to the imperfectly oxidated 
particles the degree of oxidation required, in the following 
manner- 
Stir the liquid fecula strongly, and throw over the whole 
mass a volume of warm water, double that of the fecula ; by 
this means the perfect indigo will be precipitated, and the 
other will be held in suspension by the water. This water 
is to be drawn off and treated with lime-water, by which 
the green color becomes of a yellow brown, and the indigo 
being rendered insoluble is precipitated. 

It sometimes happens, that the liquor which has been 
treated with lime-water, and beaten, if the operations have 
not been well conducted, still retains a portion of indigo 
in solution ; this can be ascertained by adding lime-water 
to a small portion of it, to see if it will become brown. 

That indigo may have the purity and brilliancy belonging 
to it, it must be twice washed, once in cold, and once in 
hot water. 

To perform the first washing, collect all the fecula in an 



310 CIIYMISTRY APPLIED TO AGRICULTURE. 

earthen pan, and pour over it four or five times its own 
volume of very pure water; stir tlie fecula very carefully, 
raisintr it with the hand in the water, and let this be re- 
peated occasionally for several hours, after which it may be 
allowed to settle ; when the fecula is entirely dejx)sited, 
turn off the water and add more, and let this be repeated 
till the water is no longer colored. As washing in cold 
water will not remove all the foreign substances which in- 
jure indigo, it is necessary to have recourse to hot water ; 
but to perform the last washing economically, it is necessary 
to collect the product of several cold washings, and to 
operate upon large quantities. 

Before commencing the washing in hot water, the fecula 
receives a certain degree of consistency by compression, 
after which it is placed in a tub and allowed to ferment 
during ten or twelve days, till it exhales a strongly acid 
odor ; by this means a mealy portion, which escapes the 
action of cold water, is decomposed. The process of wash- 
ing in hot water is next performed in the same manner as 
I have directed for the cold washing ; the operation may, 
however, be shortened, and very nearly the same results 
obtained by boiling the indigo in water, taking care to stir 
it the whole time. 

To bring indigo to the greatest degree of purity, and to 
give it the forms which it ought to have in commerce, it 
must undergo certain other processes. 

The washings in water remove all those substances which 
are capable of being dissolved ; fermentation decomposes 
certain j)rinciplcs which are foreign to the nature of indigo; 
but there still remain in it, in greater or less quantities, 
certain earths, which, according to their several proportions, 
adulterate it, and which should theref<)rc be extracted ; for 
this purpose the indigo-paste is tiirown into a vat furnished 
with two or three stop-cocks situated at various heights, and 
is there diluted with a large quanlitv of wat«T. The indigo 
is carefully mixed with the water, .-^o that all the particles 
of it may swim .separately in the li(juid ; the upper sto[>-cock 
is then oj)eno(l and the water drawn off into a i)uckct ; the 
Becond is tluri opened, and afterwards the third, and the 
indigo which the water carries off is allowed to precipitate 
itself. 

As the earthy deposit which is formed at the bottom of 
the vat contains some indigo, it is washed in a great quan- 
tity of water, which is drawn off in the same way as the 



EXTRACTION OF INDIGO FROM WOAD. 311 

first, this being repeated till no more indigo can be ob- 
tained from the deposit. 

Nothing more is necessary to be done to the paste of 
indigo when it has been freed from all foreign substances, 
than to separate from it the water which renders it of the 
consistency of porridge ; and for this purpose I shall pro- 
pose a method which I have practised successfully in some 
analogous operations. Line the inside of a basket with a 
coarse bag of woollen or tow cloth, throw the paste into 
the bag, and leave it to drain. When filtration is ended, 
cover the paste with the upper end of the bag, which had 
been turned down, and place upon it a large round wooden 
dish, which will fit the inside of the basket, and upon this 
put a weight, which is to be gradually increased till the 
fecula acquires a great degree of closeness of texture : 
if the operation be well performed, the mass can scarcely 
be broken by the hand. This cake is afterwards cut into 
squares, and dried at a temperature of between 30° and 
40°. (Probably of Reaumur, and equal to 99° and 122** 
of Fahrenheit.) The preparation of indigo is afterwards 
terminated by an operation which is called sweating. 

M. de Puymaurin states, that the most favorable time 
for operation is when, '' upon breaking an angle of one of 
the cubes, a dry noise is heard.'^ When this is the case, 
the cakes of indigo are put into a large barrel till it is 
full, when the top is covered, without having the head 
fastened in. The indigo remains in this cask three weeks, 
during which time it heats and gives out a disagreeable 
odor, it transpires a portion of water, and becomes covered 
with a w^hite down. At the end of the specified time the 
surface of the indigo is rubbed and smoothed, and it is 
then prepared for sale. 

The indigo of woad, if prepared with all the care here 
described, is equal, if not superior to the best of that 
brought from Guatimala; its effects are the same in dy- 
ing, and it differs from that neither in nature nor in char- 
acteristics. By the manufacture of this kind of indigo in 
France, a new source of agricultural prosperity may be 
bestowed upon her. 

It now only remains to be determined whether or not 
the farmer can with advantage turn his attention to the 
manufacture of woad-indigo ; for without this, though the 
discovery of the possibility of extracting indigo from the 
isatis would be in itself an important one, it would be of 
no use to the nation. 



ni2 ClIVMISTRY APPLIED TO AGRICULTURE. 

If it slioiild be ascortairjod that tliis manufactnro would 
be advantageous in peaceful times, it certainly must l)e re- 
garded as of great imj)ortance at those periods, when a 
miiritime war, by increasing the difhcnlty of procuring 
foreign indigo, shall cause the price of it in commerce to 
be greatly enhanced. Besides, if good king Henry IV. 
was willing to j»ronounce penalty of death upon the im- 
porters of indigo, in order that he might preserve to agri- 
culture the manufacture of woad cakes, why should not 
government prohibit the importation of the same article a.s 
soon as the manufacture of it from woad is established 1 
France would, by such a course, be endowed with a pro- 
duct of the value of at least 20,()0(),()()0 : she would be 
placed above the chances of war, would retain within her- 
self an immense sum which passes into foreign hands, and 
would furnish employment to the numerous population of 
the fields. 

But let us see if, in the actual state of things, the manu- 
facture of woad indigo can compete with the importation 
of it. 

An acre of land (old Paris measure) produces at the 
various cuttings 7.^ tons of woad leaves. At the lowest 
calculation, the product of an acre in leaves, especially 
in the south, may be fixed at 7^ tons, and that of the in- 
digo which they will yield, at three ounces per hundred 
weight, will make nearly 28 lbs. of indigo per acre. 

The value of gocxl indigo may be estimated at nine 
francs (a franc being about eighteen or nineteen cents), 
and this will make the value of the indigo from an acre of 
land to be 2i>2 francs. Let us now comi)are this with the 
value of wheat raised upon the same land : the (piantity 
of wheat may be estimated at about 12 hectolitres ( =: 34 
bushels), and the price at eighteen francs ; this will give 
21;'> francs per acre. We will now calculate and compare 
the expense attendant upon the cultivation of each plant. 

The preparation of the ground by tillage and manures 
is the same for the seeds of both |)lants, but the expense 
of cultivatio!! and of hand-labor ditTer es.sentially. 

Weeding by the hand is sufficient for wheat, and the 
expense of this is very triHing, w hilst the same operation 
when performed ujxjn woad, to which it is much more 
necessary, must be done with instruments which will 
loosen the earth, and root out all the noxious herbs : the 
expense of this cannot be estimated at less than twenty- 
five francs. 



EXTRACTION OP INDIGO FROM WOAD. 313 

The cutting of the leaves, which must be repeated five 
or six times, amounts during a season to about fifty francs. 

The expenses attendant upon the manufacturing pro- 
cesses cannot be estimated at less than two francs per 
pound of indigo ; this will make fifty-six francs. 

The seed necessary for sowing an acre costs about 
twelve francs, but by leaving the roots in the ground to pro- 
duce seed, this may be reduced to six francs. 

Thus, from the gross product, in indigo, of two hun- 
dred and fifty-two francs, there must be deducted 

francs. 

for weeding 25 

" cutting 50 

*' expense of manufacturing. 56 

" seed 6 



137 

Deducting this from 252 francs, there will remain a net 
product of 115 francs, (equal to between $21 and $23.) 

The expenses attendant upon cultivating and harvesting 
wheat are not so great as those for woad ; for, stating the 
price of seed at ^ of the value of the product, and the 
weeding, reaping, gathering in, and threshing, at ^, the 
whole expense would be but sixty-three francs, and this 
reduces the net value of the product to one hundred and 
sixty-three francs ; the balance would thus be in favor of 
the cultivation of wheat. 

It must, however, be remembered, that I stated the value 
of the product in indigo at the lowest. M. de Puymaurin 
has obtained five ounces, and that of a good quality, from 
1 cwt. of leaves ; at this rate an acre of land would yield 
forty-seven pounds of indigo, instead of twenty-eight ; and 
this sold in commerce even at the low price of six francs, 
would produce two hundred and eighty-two, instead of 
two hundred and fifty-two francs. An additional profit like- 
wise arises from the cakes into which the leaves are formed 
after having been nearly exhausted of their indigo ; these 
may be sold with advantage to the dyers, or if there be no 
demand of this kind for them, they form a better and more 
abundant manure than that which is yielded by the dried 
stalks and leaves of wheat. 

I may likewise add, that in those establishments which 
are in the vicinity of dye-houses, the indigo paste, which 
27 



314 CllYMISTRY APPLIED TO AGRICULTURE. 

producos the samo cfTect as the indigo cakes, may he sold, 
and tlius ilie inamifacturer may save himself tlie perlorm- 
ance of tlie three ])rincipal operations, filtration, drying, 
and sweating ; and the dyer will be spared the trouble of 
breaking the cakes. 1 am even assured, tliat by making 
use of the fecula, instead of tlie indigo, which has gone 
Uirough all the processes, the dyer can diminish the quan- 
tity of woad cakes which he uses in the composition of 
his coloring licjuor. 

It seems very evident to me that the introduction of this 
valuable branch of industry into our country, needs only 
some slight encouragement on the part of government ; 
tlie only one I would ask is, the augmentation of the pres- 
ent duty upon imported indigo of ten francs per kilo- 
gramme, (about 80 cts. per lb.) Without this, the agri- 
culturist can hardly determine to undertake a manufac- 
ture, which, though promising advantage, is new to him, 
and, if badly conducted, presents, like all others, danger 
of loss. 

I shall conclude this chapter by inviting all agricul- 
turists who are zealous for the progress of their art, to 
undertake the cultivation of the isatis tincturiu upon a 
very small portion of their ground, and in a soil suited 
to it, for the purpose of making indigo ; they may in 
this way familiarize themselves with the processes of the 
manufacture so as to be able to enter into it upon a large 
scale with confidence. 

The i.<(itis grows and prospers in all climates ; that which 
is raised in the northern departments of our country has 
been known to yield five ounces per cut. which corresponds 
to the (piantity alforded by it in the south. 

It would be wrong to be discouraged in any undertaking 
by the failure of a first attempt : neither in cultivation 
nor in manufacturing can one liope to arrive at perfection 
«t once ; time, experience, and especially close observa- 
tion, can alone enable us to overcome all obstacles, and 
so to manage our concerns as to be always sure of suc- 
ces^^. The experiments which I recommend are not costly, 
neither do they recpiire any other utensils than are to be 
found in every farm hou.se. 



CULTIVATION OF THE BEET ROOT. 316 



CHAPTER XXI. 

ON THE CULTIVATION OF THE BEET ROOT, AND THE EX- 
TRACTION OF SUGAR FROM IT. 

I FEEL myself authorized by ten or twelve successive 
years of experiments and observations upon the cultiva- 
tion of the beet root, and the extraction of sugar from it, 
to publish some results which may be relied upon. 

As this new branch of industry is capable of being ren- 
dered a fruitful source of agricultural prosperity, I shall 
be pardoned if I enter into all those details which I con- 
sider necessary for directing the agriculturist, that he may 
not try such experiments and commit such mistakes, as 
often lead to useless expense and are always discouraging. 



SECTION I. 
On the Cultivation of the Beet Root. 

Beet seed is sown in the latter part of April and the 
beginning of May, when there is no longer any danger of 
the return of frost. I have sown it with good success 
towards the middle of the month of June ; it is better, 
however, to sow it neither too early nor too late. If it be 
sown immediately after the cessation of the frosts, the 
ground being cold and very wet, the seed does not germi- 
nate immediately, and the soil, becoming hardened by the 
violence of the rains, does not admit the air to penetrate, 
so that if the seed do not decay, the beets come up badly ; 
when sown late, they suffer from evils of another descrip- 
tion ; the rains will then be less frequent, but the great 
heat dries up the ground, and those soils that are rich and 
compact form a crust, which the tender plumule of the beet 
cannot pierce. Those seeds which are sown at the right 
season have to encounter the danger of being stifled by a 
host of strange plants that spring j.ip with them, and which 
render weeding very expensive. The most favorable period 
is that when the earth, although heated by the rays of 
the sun, still contains sufficient moisture to produce ger- 



316 CHYMISTRY APPLIED TO AGRICULTURE. 

minatioii, and to facilitate the growth of the yoiiiifr plant : 
tlie last (lays of April and the first fifteen days of Maj 
generally unite; tiiese advantages. 



ARTICLE I. 

On the Choice of iSccd. 

A nooD afjriculturist should always raise his own seeds: 
for this purpose he will [)lant his beet roots in the spring 
in a good soil, and gather the seed in September as fast as 
it ripens, selecting only the best, and leaving ujK)n the 
stalks such as are not thoroughly ripe ; each beet root will 
furnish from five to ten ounces of seeds. 

When no care is taken in selecting the seeds, and they 
are sown indiscriminately, not only are many of the beets 
small, and ill grown, but half of the seeds sown do not 
yield any thing. 

Beets vary in color, some being white, others yellow, 
red, or marbled ; there are even some of which the skins 
are red and the substance white : it is generally known, 
that seed from a beet of one color does not always j)roduce 
the like : a field which is sown with tlie seeds of yellow 
beets alone, will invariably yield some roots of the other 
colors. 

Too much importance has hitherto been affixed to the 
color ; I have never myself ob.served any considerable dif- 
ference in the products of the different kinds ; however, I 
cultivate from preference the yellow and the white, be- 
cause the process of refining the sugar made from red beets 
requires a little more time ; for although the lime which is 
employed in the first operation instaiitlv deprives the juice 
of color, yet it accjuires, during concentration in the boiler, 
a brownish tinge, which the sirup from white and that from 
yellow beets does not receive. 



CULTIVATION OP THE BEET ROOT. 317 

ARTICLE II. 

On the Choice of Soil* 

All corn lands are more or less adapted to the cultiva- 
tion of beets ; but the best soils for the purpose are those 
that have the greatest depth of vegetable mould. 

Sandy soils formed by alluvions and the deposits of 
rivers are also very favorable to the growth of beets ; nor 
is any other artificial manure necessary upon spots so 
situated as to receive it, than the mud which is periodically 
deposited by inundations. 

Beets may be cultivated with good success upon natural 
or artificial grass lands ; but I have always observed, that 
beets came up badly when sown in the spring upon such 
lands as had been broken up in the autumn, and ploughed 
two or three times during the winter : the turf and roots 
do not in so short a time become sufficiently decomposed ; 
and in order to have good beet roots, I find it necessary to 
raise a crop of oats between the time of breaking up a 
meadow and sowing it with beet seed : after this I can 
raise two successive crops of the finest beets. If the soil 
of a natural grass land is dry, or not closely united, it may 
be sown with beet seed six months after being broken up ; 
but I have never obtained good harvests of beets from clo- 
ver lands without having first sown them with a crop of 
grain : in these lands the beets have always been better 
the second year than the first. 

Dry, calcareous, and light soils are but little suited to 
the culture of this root. 

Strong clayey soils are not well adapted to the cultiva- 
tion of beets ; in order that these roots may prosper, it is 
necessary that they should grow in a loose, fertile soil, hav- 
ing a bed of vegetable mould of at least twelve or fifteen 
inches in depth. 

Beets prosper to a certain extent in all arable lands, 
but the quantity as well as quality of the product varies 
surprisingly with the nature of the soil. Good soil will, 
furnish 100,000 lbs. per hectare, (=. 2 acres, 1 rood, 35 
perches English ;) a poor soil only from 10,000 to 20,000 
lbs. 

Upon several hectares of lands of very different nature, 
27* 



318 CIIYMI8TRY APPLIED TO AGRICULTURE. 

u'hicli I put in cultivation each year, tlic average rate of 
production is 40,000 lbs. 

The value of beets cannot be calculated by the gross 
weight ; the large roots, which often weigh from ten to 
twenty pounds, contain a large proportion of water, and the 
j>pecific gravity of the juice extracted from such will not be 
more than 5^ or ()° of the hydrometer (zir 1.03G to 1.044,) 
whilst that of beets weighing a pound less will rise as high 
as 8° or 10° {= 1.000 to 1075,) so that the juice of the last 
contains in the same volume nearly twice as much sugar 
as does that of the first, and the extraction of it is easier 
and less expensive, because less time and I'uel are required 
for evaporation. I therefore prefer, in my manufactory, 
beets which weigh one or two pounds, though the soil up- 
on which I raise them should not yield me more than from 
25,000 to 30,000 lbs. per hectare. 



ARTICLE III. 
On the Preparation of the Soil. 

Generally speaking, I cultivate beets upon all such 
lands as are appropriated for sowing grain upon in the fall. 
The lands I prepare for receiving the seed by three good 
tillings, two of which are performed in the winter, and one 
in the spring : by this last ploughing the dung which is 
thrown upon the ground after the second, is mi.ved with it : 
the quantity of manure employed is the same as if the 
ground was to be immediately sown with wheat. 

When the cultivation of the beet was less known than 
it is at present, it was thought that the use of dung rendered 
the root less rich in sugar, and more disposed to |)roduce 
salt-petre ; my own observations have never veriiicd the 
truth of this opinion, nor have I ever perceived any other 
difference than that of size between beets raised in ground 
dressed with barn-yard manure, and those raised in a soil 
not so prepared. That which has given rise to the error 
is the greater (juantity of sugar contained in the same vol- 
ume of small beets, in consequence of the more concen- 
trated state of their juices. 



CULTIVATION OF THE BEET ROOT. 319 

ARTICLE IV. 

On the Manner of Sowing Beet Seed. 

Beet seed may be sown in either of the three following 
methods. 1. in a seed plot: 2. in drills: 3. broad-cast. 
The first of these ways offers to the agriculturist the ad- 
vantage of requiring much the least time at a season of the 
year when every moment is precious : the young plants 
may be transplanted in June before the commencement of 
the hay harvest, so that the cultivation of beets need not in 
any way impede the ordinary labors of the fields. There 
are however, some serious inconveniences attendant upon 
this mode of sowing : the first of these is the care that is 
requisite in pulling up the young plants so as not to leave 
behind a' portion of the root ; for if a tap-root be broken 
off, it ceases to increase in length, but grows in circum- 
ference, and throws out radicles from its surface in every 
direction. The second difficulty is, that if, in placing the 
root in the earth, its long and very slender point be bent 
upward, its growth in length is frustrated in the same 
manner as if it were broken off. It ia however advisable for 
the farmer to sow a portion of his beet seed in a seed plot, 
in order that he may be able to fill the vacancies which 
will always be found in fields sown by the other methods. 

But seed may be sown broad-cast in the same man- 
ner as grain, and in this case sowing may be com- 
menced as soon as the ground has been well prepared by 
ploughing and rollmg. The seed is covered by having a 
harrow passed over the ground in two directions, crossing 
each other. This method requires at least from eleven 
pounds and a half, to thirteen pounds and a half of seed 
per hectare. 

This last process is the one most generally made use of, 
and the one which I myself employed during seven or eight 
years ; but I now give the preference to the method of 
sowing in drills, as being more sure and more economical. 
For this purpose, as soon as the ground is prepared, I trace 
upon the surface, by means of a harrow armed with four 
teeth, distant about eighteen inches from each other, fur- 
rows of an inch in depth ; the seed is dropped into these 
furrows at intervals of sixteen inches, by women or girls 
who follow the harrow, and who cover the earth over the 



3*20 ClIVMISTRY APPLIED TO AGRICULTURE. 

Feeds with tlieir hands, Ericli woman can sow, in this 
manner, t^ix or eiglit thousand seeds in a day. 

The quantity of seed necessary in this method, is a little 
less than half what is required for sowin*^ broad-cast, and 
the weeding of the beets is much easier, and by no nteans 
PC expensive. 

The method of sowincT beet seed which has been adopt- 
ed in England, can scarcely fiiil of being successful : it 
consists in opening a deep furrow, in the lK)ttom of which 
is placed a portion of the manure which is to be used upon 
the land ; a second furrow is then drawn paralhd to the 
first, and so near it that the earth thrown up shall cover 
that over : the second trench is prepared in the same man- 
ner as the first, and so on ; the seeds being sown immedi- 
ately over the manure. By this disposition of the ground 
the roots easily penetrate through the loose soil to the dung, 
which retains its moisture, and furnishes the plants with 
nourishment. 

But whatever mode may be followed in sowing beet seed, 
it is necessary to observe the three following rules : first, 
to sow only new and naturally fertile soils ; second, not to 
place the seed at the depth of more than an inch ; third, 
not to sow the seeds too thickly. 



ARTICLE V. 

On the Care required by Beets durinir tfuir Vegetation. 

There are few plants that require more care than beets : 
their developemont is greatly impeded by the neighbour- 
hood of other plants, and if the soil be not light and loose 
around them, they languish, turn yellow, and cease to 
grow. 

When beet plants begin to sljow their second leaves, 
they must be weeded : if they have been sown broad-cast, 
this can be done only by the hand or with a small hoe or 
weeding fork ; all the weeds must be rooted up, and as 
many of the plants removed as will leave spaces of eigh- 
teen inches between those that remain. If the plants are 
sown in furrows, the j)lough may be passed between the 
rows, and the roots of the plants be cleared with the weed- 



CULTIVATION OP THE BEET ROOT. 321 

ing fork. The same operation must be repeated at least 
twice in a season. 

As weeding opens the earth to the free entrance of air 
and water, the plants may be seen to be benefited by it ; 
the green of their leaves deepens, their roots increase in 
size, and their foliage expands. 

Since I have sown my fields in drills, I have practised 
passing the plough through them three times in the course 
of a summer, and at each time I have made thorough use 
of the weeding-fork around the roots of the plants. 

Half a day's use of the plough is sufficient for half a 
hectare, and the rest may be completed in a day by five or 
six men. I find that I save one half the expense of weed- 
ing by employing this method. Each weeding with the 
fork costs at least twenty francs per acre. The produce 
of a field which is well taken care of, is at least double that 
of one which is neglected. 



ARTICLE VI. 
On the Gathering of Beet Roots. 

Beet roots are generally dug during the month of Octo- 
ber : the digging should be completed before the com- 
mencement of the frosts. When surprised by untimely 
frosts, if the roots cannot readily be transported to a place 
of shelter, they may be collected in heaps upon the fields 
and covered over with their own leaves : those that remain 
in the earth are in much less danger from frost than those 
that have been dug. 

The time mentioned in the preceding paragraph is the 
one most suitable for the vicinity of Paris, and for the 
centre of France ; but as vegetation is more forward in the 
southern departments, it is necessary that beets should 
there be gathered earlier in the season, otherwise the sac- 
charine principle may disappear, in consequence of a new 
elaboration of the juices after maturity The fact appears 
to me to have been fully ascertained by the experiments of 
M. Darracq. This able chymist, in concert with the Count 
Dangos, Prefect of the Department of Landes, made every 
arrangement for the establishment of a sugar manufactory. 



332 CHYMISTRY APPLIED TO AGRICULTURE. 

During the months of July and August, he made experi- 
ments upon beets every eight days, and always ol>tained 
from three and a half to four per cent, of good sugar. 
Satisfied with these results, he discontinued Ids experiments, 
in order to devote all his time to the care of his establish- 
ment ; but how great was his surprise at finding towards 
the end of October that his beets yielded only sirup and 
salt-petre, and not a particle of crystallizable sugar. 

Generally speaking, beets may be dug as soon as their 
largest leaves begin to turn yellow. If harvested before 
arriving at maturity, they wither, wrinkle, and grow soft : 
the juice is extracted from them in this state with more 
difficulty, and the sugar does not grain so well. 

The leaves, which are separated from the roots as fast 
as they are taken from the ground, may be left upon the 
spot and there eaten by cows, sheep, or swine ; but they 
are so abundant that there will still remain enough to serve 
as a half manure for the land, and it is in this soil, after 
having slightly ploughed it, that 1 sow my grains. As the 
earth has been manured in the spring, and afterwards freed 
from weeds by repeated hoeings, the corn will grow very 
large and be very clean ; so that the first tillage and ma- 
nuring serve for two harvests, and the ploughings which 
are given in autumn to lands appropriated to the reception 
of wheat or rye, are saved. 



ARTICLE VII. 

On the best Method of Keeping Jiect Roots. 

Beets are affected both by cold and boat : they freeze 
at a temperature one degree below the freezing point of 
water, and they germinate with a degree of heat but little 
above frfozinir : freezing softens tlirm and destroys their 
saccharine i)rincij)le, and they decay as soon as they are 
thawed. Heat developes the stalks at the necks of the 
roots, and decomposes the juices which siij)plv tlioir growth. 
During the first stages of germination, the alteration of the 
juices is only local ; so that if the neck of the root be cut 
off, the remainder of it may be made use of without any 
inconvenience. In order to keep beets, it is necessary to 
preserve them both from heat and cold. 



CULTIVATION OF THE BEET ROOT. 3*23 

The first care of the farmer must be, to have his beets 
thoroughly dry before being housed. The best way is to 
leave them in the fields till all their dampness has evapo- 
rated. When, however, a large harvest is to be gathered 
in autumn, a sufficient number of fine days to effect this 
can hardly be hoped for, and the roots must therefore be 
stored for the winter in such a manner as will be most likely 
to prevent decomposition. 

I have an immense barn, where I pile up my beets to the 
height of seven or eight feet, as fast as they are carried 
from the fields. I make use of no other precaution than 
that of forming against the surrounding walls a layer of 
straw or broom, which rises as high as the pile of roots ; 
when the frosts set in, I cover the pile over with straw ; and 
in this way I have for ten years preserved my crops of beets 
uninjured by them. It has, however, happened two or three 
times, that the roots began to germinate with so much 
energy, that I was fearful they would become decomposed. 
In these cases, I unstacked and spread the beets, and thus 
arrested the process of vegetation. 

Some farmers leave their beets in the field. In order to 
preserve them, they dig a trench in a dry soil, giving the 
bottom a gentle slope, that water may flow off" easily. This 
trench they fill with the roots, and cover it over with a bed 
of earth a foot thick ; upon this they throw heath or broom, 
to prevent the rain from penetrating. Some line the bottom 
and sides of the trench with straw or heath. 

Instead of being put into trenches, the digging of which 
is always expensive, the beets may be preserved in the 
fields by forming heaps of them upon a dry soil, and covering 
the tops and sides with layers of earth ; or they may be 
covered over with a roof like the one I have heretofore 
described. This method of preserving roots may be em- 
ployed when there is no suitable storehouse for them ; or 
when the means of conveying them to one in autumn are 
wanting. 



324 CHVMISTRY APPLIED TO AGRICULTURE. 

SECTION 11. 

On the Extraction of Suoar from Beets. 

I shall not here describe the numerous difficulties that 
linvc Ikm'ii encountered before arriving at sure methods 
and certain results. I shall confine myself to the descrip- 
tion of the simplest and most advantageous processes that 
are employed at this time ; and I will draw my examples 
from my own practice, enlightened as it is by twelve years 
of experiment and observation. I have successively execu- 
ted all tlie known processes ; I have tried all the improve- 
ments that have been suggested ; I have myself regulated 
and improved some of the processes ; and 1 shall describe 
only such as I have proved and confirmed. 



ARTICLE I 
On the Preparation of the Roots. 

Before subjecting the beets to the teeth of the rasp, they 
must be carefully freed from all the earth which they bring 
with them from the fields. The necks, and any portion 
that has begun to decay, must be cut off, and the radicles 
removed from the surface. 

In many manufactories, nothing more is done to the 
roots than to wash them. But this operation cannot be 
conveniently practised in all places, and I have therefore 
dispensed with it as a preliminary ; nor have I found any 
bad effect to arise from the omission of it. Eiirlit women 
can easily prepare 10,000 lbs. of the roots in a day. 11 
the beets are large, and retain but little earth about them, 
the same numlu-r of women can prepare in the same time 
from 15 to 20,000 lbs. 



EXTRACTION OP SUGAR PROM BEETS. 325 

ARTICLE II. 

On the Method of Rasping the Beet Roots 

The beets, when well cleansed, are submitted to the 
action of a rasp, by which their fibrous substance is 
reduced to a pulp. The rasp is worked either by a horse, 
or by a stream of water. The rapidity of its motion should 
be equal to four hundred revolutions upon its axis in a 
minute. 

The rasps used by me, are sheet-iron cylinders, fifteen 
inches in length, and twenty-four in diameter, having their 
surfaces furnished with ninety iron plates armed with saw 
teeth, and fixed by screws perpendicularly to the axis of 
the cylinder and throughout the whole length of it. 

The beets being pressed against the rasp, by means of a 
piece of wood held in the hand, are immediately torn in 
pieces. The pulp falls into a box lined with lead, which 
is placed beneath. The table upon which the beets des- 
tined to the rasp are placed, is so near the instrument as to 
allow only sufficient space between for the passage of the 
pulp. 

The operation of rasping must be conducted expedi- 
tiously, otherwise the pulp begins to turn brown, fermen- 
tation takes place, and the extraction of the sugar is 
rendered difficult. By the use of two rasps, put in motion 
by the same horse, I have reduced 5000 pounds of beets to 
a pulp in two hours. The pulp should not contain any 
portion of roots that have not been acted upon by the 
instrument. 

Compression will not in any degree supply the place of 
rasping. The strongest presses can never extract from 
beets more than from -f^^ to -f-^^ of their juice, whilst the 
pulp, if properly managed, will yield from -^-^jj to -^^^. 



ARTICLE III. 

On the Extraction of the Juice, 

As fast as the pulp falls into the box placed under the 
rasps, it is put into small bags made of very strong cloth 

28 



320 ClIYMISTKY AriLILU TO AGRICULTURE, 

wovpii of pack-tliroad. Tliosn hnjrs arc placod upon the 
plate of a good iron screw press, and submitted to a strong 
pressure. The screws are after a time to be loosened, the 
places of the sacks chancred, the pulp which they contain 
shaken over, and the whole ajrain submitted to the action 
of the screw. 

Sometimes the pulp is first acted upon by a cylindrical 
press, by which alK)ut ^,^"^,y of its juice is extracted, and the 
operation is afterwards completed by means of the screw 
press. But 10,000 pounds of beets may be pressed in a 
day by the last alone. 

The pressure should be continued till the ])ulp will not 
moisten the hand when strongly scjueezed in it. The 
juice which flows from the press, is carried by leaden 
pipes into the boiler, where it undergoes the first opera- 
tion. Of this I shall speak immediately. 

If an iron screw press is not to be had, a wine press, a 
lever press, or a cylinder press will answer the purpose. 

The operation of the press should be completed nearly 
at the same time with that of the rasp. Every thing that 
has been moistened with the juice, must then be washed 
so as to be ready for a new operation. The utmost clean- 
liness must be preserved, otherwise the rasps will become 
rusty, the juice will change, and the boiling will be rendered 
dillicult. 

The juice extracted from beets, is not always of the 
same degree of concentration. Jt varies from 5^ to 10\ 
(=r specific gravity of l.O'Jt) to 1.075,) according to the size 
of the roots, the nature of the soil in which they grew, and 
the state of the atmosphere during vegetation. 

The juice of the lartje roots is less concentrated than that 
of the small ones. The juice of such as grow in a linlit 
soil, and have been exposed to heat and drought, marks 
11°, (=r specific gravity of 1.0H3;) but there is but little 
of it. The greater the specific gravity of the juice is, the 
greater is the proportion of sugar contained in it; and, of 
course, the greater is the saving of labor in the extraction 
of the surrjir. 



EXTRACTION OF SUGAR FROM BEETS. 327 

ARTICLE IV. 

On the Purification of the Juice, 

As soon as the boiler which receives the juice is one 
third full, the fire is kindled; and, as the juice continues 
to flow, the heat is raised to Go'' of Reaumur,* (z=: 180f° 
of Fahrenheit.) Whilst the juice is heating, some milk of 
lime is prepared, by pouring gradually some warm water 
into a bucket containing ten pounds of lime.t 

As soon as all the juice has passed into the boiler, and 
become heated to the degree mentioned in the last para- 
graph, the milk of lime is thrown into it, the greatest care 
being taken to stir and mix them well together ; after 
which the temperature may be raised to the boiling point. 
As soon as the first bubble makes its appearance through 
the thick glutinous scum which rises upon the top of the 
liquor, the fire is immediately extinguished by throwing a 
pailful of water into the fire-place. The scum thickens, dries, 
and hardens by rest. The juice becomes clear, and takes 
a light yellow hue. When there can no longer be seen in 
it particles either of lime or mucilage, the scum is removed 
with a skimmer and thrown into a bucket, in order that 
the juice which it contains may be expressed. The upper 
stop-cock is then opened, and the liquor is suffered to flow 
into the evaporating boiler. 

The juice does not become clear in less than an hour, 
and evaporation ought not to be commenced till it is per- 
fectly limpid. 

* I have worked 10,000 pounds of beet roots per day, at two operations 
of 5,000 pounds each. The first began at 4 o'clock, A. M., and the 
other at noon. The round boikn-, which received the juice of one ope- 
ration, was five feet and six inches in diameter, and three feet eight 
inches in depth. 1 had a separate boiler for each operation, and each 
boiler had two stop-cocks, one close to the bottom and the other five 
inches above. Between these two boilers, there were two vessels 
fifteen inches deep, and each of sufficient capacity to receive all the 
juice of an operation. In these, evaporation is carried on. The rims 
of all these boilers should be very wide, so as to cover the thickness 
of the wall in which they are set. 

My rasps and presses are placed upon the first floor, in order that the 
juice may flow through leaden pipes into the boilers, which are upon 
the ground floor, and thus save the labor of transportation. By this 
arrangement, I can have my depuratory boilers so much raised, that, 
upon turning the stop-cocks, the juice will flow into the evaporating 
vessels. 

t My boiler contains 475 J gallons of juice ; so that I employ the lime 
in the proportion of about 46 grains, troy. 



328 CHYMISTUY AIM'LIllD TO A(;KHL LTLRE. 

As sooFi as all Ii(|u<>r al)ove tho \v\o\ of the iippor stop- 
cock has passed out, tlic second st(ip-cork is tnrrnMl ; and if 
the liquor flowing through that be found clear, it is mixed 
with the first j)ortion. If, on the contrary, it apj)ears cloud v, 
the stojHcock is again closed to give it time to settle, and 
it is not made use of till towards the termination of the 
cva|)oration. 

The deposit which is formed at the bottom of the boiler, 
renders the last portion of the juice turbid. But as soon 
as tiiis is seen to be the case, that which remains is drawn 
oif into the bucket containing the scum. 

The deposit which is formed at the bottom of the boiler, 
and this scum, are exi)ressed by means of a lever press of 
very simple and cheap construction, and which is very easi- 
ly worked. 

I place a cylindrical willow basket upon a block of stone 
three feet scpiare, the upper surface of which is slightly 
inclined and furrowed witli channels an inch deep, uniting 
in a common centre at the lowest angle. The basket is 
lined with a bag of coarse cloth, the end of which turns 
back and hangs down. Into this bag I j)ut the deposit 
and scum ; then, drawing the edges of it together, I tie 
the mouth closely with a pack-thread. I place on the top 
a wooden trencher of the diameter of the inside of the 
basket. This 1 load with several square pieces of wood, 
which project over the upper part and serve as a fulcrum 
for the lever. When things are thus far arranged, I pro- 
ceed to adjust the lever, which is live feet long. This is 
fixed at one end to a ring-bolt which passes through a 
stone. The other end I load with weights to tlie amount 
of from 5(1 to 1 1*2 pounds, increasing them at pleasure, so 
as to produce a gradual and constantly increasing pres- 
sure, which may be rendered as jMjwerful as is necessary. 
The juice which is thus forced out, flows into a bucket 
and is thrown into the evaporating vessel. 

The most diflicult operation to be performed, is that of 
purifying tlie juice ; and if this be not thoroughly done, 
the processes of evaporation and gr;iiriing are long and 
troublesome ; the juice swells and bubbles up in the boiler, 
and the sugar crystallizes imperfectly and remains mixed 
with molasses. The lime which is thrown in to clarify the 
juice does not always rise to the top with the scum, by a 
prolonged period of rest in the depuratory l)oiler ; neither 
is it always precij)iiated. It sometimes happens, that, not- 



EXTRACTION OP SUGAR FROM BEETS. 8^ 

withstanding all the care that can be taken, the liquor 
remains cloudy ; and in such cases it is always in vain to 
look for good results. I have endeavoured to ascertain the 
ca!ise of these accidents, and I have sought to remedy the 
evil. I shall report here only what appears to me to be 
fully established by experiment and observation. 

The juice does not purify well if the beets have begun 
to germinate too strongly, or if they have begun to decay, 
or have been frozen. 

When the operations of the rasps and presses are con- 
ducted too slowly, so that the juice stands five or six hours 
before being purified, decomposition commences, and good 
results are never obtained. 

If all the utensils employed are not carefully washed 
after each operation, so as to free them thoroughly from 
the juice adhering to them, the labor becomes difficult 
and unsuccessful. 

I found, upon one occasion, that beets which had been 
kept in a cellar, where they had neither frozen nor ger- 
minated, did not, when subjected to experiment in March, 
yield sugar. They appeared perfectly healthy, though a 
little softer than those that had been kept in barns. 

If the first operations are not well conducted, the results 
are always bad. I can only point out the steps that can be 
taken to prevent this. 

Beets that have been well kept, may be worked with 
equally good success from the beginning of October to the 
end of March. 

When the juice does not become clear, a small quantity 
of sulphuric acid may be thrown into the evaporating ves- 
sel, a little before the liquor begins to boil. This will 
remedy any trouble arising from the use of too large a 
quantity of lime. It will, however, be useless, if the faults 
proceed from an altered state of the beet juice. 

By making use of a portion of animal charcoal to clarify 
the liquor, the evaporation of the juice and the graining of 
the sugar is sure to be rendered more easy ; but the quan- 
tity of sugar obtained is very small. 

The lime used in the process of purification combines 
with the mucilaginous principle of the beets, and neutral- 
izes the malic acid contained in them ; after this operation, 
the juice weighs 1° or 1.5° less than before. 

38* 



330 CHYMISTRY APPLIED TO AGRICULTURE, 



ARTICLE V. 

On the Concentration or Evaporation of the Purijicd 

Juice. 

As soon as the bottom of tlie evaporating vessel is covered 
with juice, the fire is kindled, and ebullition is produced as 
speedily as possible, — the juice which continues to flow 
from the clarifying boiler supplying the loss occasioned by 
evaporation. 

When the boiling juice marks 5°orG° (= 1.030 to 1.044) 
of concentration, a portion of animal charcoal is thrown in, 
and this is continued, the quantity being gradually increas- 
ed, till the juice is concentrated to 20^, (== 1.161.) Sixty 
pounds of charcoal are used in this manner, for a quantity 
of juice equal to from \'2'2 to 475 gallons. 

After having brought the liquor to the twentieth de- 
gree of concentration, the boiling is continued till the 
sirup marks 2?^ or 28° of the hydrometer, {z=. specific 
gravity of 1.231 to 1.242.) The sirup, being mixed with 
animal charcoal, requires to be filtrated. This operation, 
as it is usually performed, is very tedious, and sometimes 
becomes impracticable ; the consistency of the sirup is in- 
creased two or three degrees by cooling, and the pores of 
the filter becoming, in a short time, obstructed by the 
finely divided charcoal, the thickened liquor can no longer 
pass through them. 

To obviate these inconveniences I })lace a large willow 
basket over a boiler ; into the basket I put a coarse bag of 
the same diameter, but about two feet deeper. I pour 
the tliickenod sirup into the bag ; for some minutes filtra- 
tion goes on very well, but as the liquor grows thick in 
consoijuence of its cooling, filtration slackens and at 
length stops ; as soon as 1 perceive this, I turn the borders 
of the sack into the basket, and upon them j)Iace a wooden 
trencher, which I gradually load with cast-iron weights 
till the necessary pressure is produced ; filtration is by this 
means completed in two or tliroc hours. 

The charcoal contained in the sack is hjachcd with 
warm water, and afterwards submitted to the lever press, to 
force; from it all tlie siruj) contained in it. The waters 
used f(jr those hMchings during one day, are the next day 
mixed in the clarifying boiler with the juices that are then 
prepared. 



EXTRACTION OP SUGAR FROM BEETS. 331 

The conversion of the juice into sirup should be done 
as speedily as possible ; for when evaporation is slow the 
liquor becomes pasty, as part of the sugar is decomposed 
and passes to the state of molasses, and the difficulty of 
boiling is increased. It is necessary then that evaporation 
should be carried on with violent boiling, and for this rea- 
son the boilers made use of should be broad and shallow, 
so as not to heat only layers of the liquor, and in order 
that ebullition may take place at once through the whole 
mass of the liquid ; the furnaces likewise should be so 
built as to heat the boilers equally. The evaporation of 
422 gallons should be completed in four hours. 

The operation is known to be good, and the juice to have 
been well prepared, when ebullition takes place without 
causing the liquor to swell and blister ; when there ap- 
pears on the surface only a brownish foam, the bubbles of 
which disappear immediately upon being pressed with a 
spoon, and when a dry sound is produced by striking upon 
tJie liquor. 

If, on the contrary, there forms a whitish, gluey foam, 
which does not subside, the operation is bad ; evaporation 
requires a long time, and the boiling is difficult. In this case 
a little butter is, from time to time, thrown upon the sur- 
face to quiet the effervescence ; the quantity of animal 
charcoal is increased, and the fire is checked. All these 
palliatives, however, do not correct the radical fault, and 
such appearances always presage bad results. 



ARTICLE VI. 

On Boiling the Sirup. 

The sirups prepared over night are the next day dried 
to extract the sugar from them. 

The products of two operations upon 5000 beets are 
mixed together in a boiler, whence they are taken to form 
four successive dryings or boilings. One fourth part of 
these sirups is thrown into a round boiler, forty inches in 
diameter and twenty in depth ; under this a fire is kindled ; 
the liquor is made to boil, and the boiling continued till the 
operation is ended. 



33*2 CHYMISTKV AI'I'LIKD TO AliKlL I L I L Ui:, 

Tlie process is judged to be going on well if tiie li(iaor 
exhibits tiic following symptoms. 

I. When the siruj) breaks short, and the bubbles upon 
returning into it produce a sensible sound. 

ti. Wiien a dry sound, like that produced by striking 
silk, is returned from the surface of the sirup when it is 
fJtruck with a skinnner. 

3. Wiien the bubbles of foam disappear immediately 
upon being pressed with a spoon. The boiling is always 
j)erfect when the interior surface of the boiler is found, af- 
ter the operation is ended, to retain no trace of blackness. 

The sirup is known to be bad by the following signs : 

1. When a thick, whitish, gluey foam appears upon 
the surface of the liquor. 

2. When the litjuor swells and foams, and does not 
subside. 

3. NV'hen tlic escape of pulfs of acid steam announces 
that the boilinw substance is burnt. 

The evils are j)aUiat('d and the boiling terminated, 

1. By removing the foam as fast as it forms. 

2. By throwing into the substance small pieces of 
butter. 

3. By stirring the liquor with a large spatula. 

4. By mi.xing with it a little animal charcoal. 

5. By moderating the heat. 

To avoid a ])ortion of these evils, I throw a flood of 
sirup into the boiler, and remove the whitish foam that 
arises ; I stir the sirup strongly three or four times before 
boilins commences, and skim it each time. The scum 
that is removed is thrown into a bucket with that which is 
produced during all the time that the liquor is boiling ; 
these skinnnings are afterwards subjected to the lever 
press, and the remainder washed, to obtain from it all the 
juice contained in it. The sirup obtained by pressing up- 
on one day, is added to the liquor that is boihd the next, 
and the water of the leaching is thrown into the evaporat- 
ing boiler. 

When the sirup in the drying vessel shows itself to be 
bad, especially when it gives out pulTs of sharp steam, 
which declare the substance to be burnt, it is necessary to 
arrest the process and to treat the sirup with an additional 
portion of aniiiiiil charcoal. In this case the KKpior is di- 
luted with water till it falls to IH° or 20° of concentra- 
tion, (= specific gravity of 1.143 to 1.1(31,) and then the 



EXTRACTION OF SUGAR FROM BEETS. 333 

charcoal is added ; after which ebullition is renewed till the 
sirup rises to 28°, (= 1.242,) when it is filtered and dried, 
I have found this to be the only way in which I 
could restore a sirup which had been injured in the 
process. 

I have myself made particular observations upon the 
thick, whitish, unctuous and paste-like substance, which 
is almost always found upon the sirup, and which, when it 
is abundant, prevents the drying from being well-termi- 
nated. This substance renders the sirup ropy, adheres to 
the sides of the boiler, which are blackened by it, separates 
itself from the sirup, in proportion to its concentration, and 
prevents the object proposed from being attained. 

I have noticed that the quantity of this substance was in 
proportion to the germination of the roots, and that it was 
increased by the incomplete purification of the sirup, and 
also by a slow evaporation. Animal charcoal produces an 
astonishing effect in lessening the quantity of it ; sometimes, 
if well employed, the formation of it is prevented, or that 
which is produced is made to disappear. 

This substance, which, during the first years of my es- 
tablishment, I often collected in large quantities, is thick- 
ened and hardened by cold ; it is insoluble in water or 
alcohol ; it burns with a white and inodorous flame ; and 
possesses all the characteristics of vegetable wax, from 
which it is in no wise different. 

The drying is ended when the boiling sirup marks 44® 
or 45°, (=: specific gravity of 1.440 to 1.454.) The time 
for removing the sirup from the boiler may be known by the 
following signs. 

1. Plunge a skimmer into the boiling sirup, and upon 
withdrawing it pass the thumb of the right hand over its 
surface ; mould the sirup which adheres to the thumb be- 
tween that and the fore finger, till the temperature be the 
same as that of the skin ; then separate the thumb and 
finger suddenly ; if the boiling be not completed, no thread 
will be formed between the two ; if there be a filament, the 
boiling is well advanced ; and the process is completed as 
soon as the filament breaks short, and the upper part, hav- 
ing the semi-transparency of horn, curls itself into a spiral. 
This manner of trying the sirup is known by the name 
proving. 

2. The second mode of judging of the completion of 
the process, is by observing the time when the sirup ceases 



JjJ^4 CHi.\lI>lKV AI'I'i-lKi. TO AGUICULTURE. 

to moisten iIjc si«k*s ol' ilie boiler, ami liieii Wlowing forci- 
bly into a skimiiKT which has just been immersed in it; if 
bubbles escape throncrh the holes of the skimmer which 
ascend into the air in tiie same manner as soap bubbles do, 
the li(iuor is considered to be sufficiently boiled ; the fire is 
therefore immediately extin<ruished, and the sirup is a few 
minutes after conveyed to a great copper boUer, which is 
called the cooler. 

The cooler is placed in an apartment of the manufac- 
tory near the boilers ; its capacity should be such as to al- 
low of its receiving the product of the four successive 
boilings. The cooling which the sirup exj)eriences in this 
vessel, quickly produces crystallization; the crystals form 
first at the bottom, where they collect in a thick bed, hav- 
ing, however, no union of ])articles. Gradually the sides 
become covered with solid crystals, and at length there is 
formed upon the surface a crust of sugar which thickens 
insensibly. At this time the contents of the cooler are 
taken out to fill the moulds in which the process of crys- 
tallization is to be completed.* 

The contents of the cooler are first thoroughly stirred 
and mixed, and then thrown gradually into the moulds, a 
portion being put into each in turn, so as to fill them all 
equally : an interval of an inch is left between the surface 
of the sirup and the top of the mould. 

Crystallization is hastened by carrying the moulds, as soon 
as they are full, into the coolest apartment of the manufac- 
tory.t 

* The mould.s used in this operation are known in refineries by the 
name of irraudcs Ix'iUinlcs. Tlicy are lari^re conical vessels of baked 
earth, with <a small openinjr at tlie apex, and capable of containinjj 
about 1(10 pounds of the evaporated sirup. The ditferent sizes are 
distintjiiished in the manufactories aa omndcs et jietitis hdtardrs, ac- 
cordinir to their dilferent capacities ; they are nunilx-red I,'-2.".i. 4, «.V:c. 
Moulds made of resinous wood have su])plied the place of these in 
some manufactories ; this chancrp was proposed by M. Mathieu de 
Dombasle, and in those countries where wood is abundant, it is a good 
one in point of economy. 

Tlie moulds must be soaked in water, and then drained, btT.re the 
sirup is put into them ; the openini;^ at the point is stopped with old 
hnen, and the vessels themselves suj)ported against the walls to re- 
ceive the li(|uor. 

t The siruj) arising from the employment of 10,000 pounds of beet 
roots, if the ojierations are well conducted, will fill nine irronilci hn- 
tordes, each h.'Uiirilc containing frcun c;') to !)0 pounds of evojiorated 
sirup. 

When Uie dilVt-rent boilings are made slowly, or experience any in- 
terruption, the moulds are partially filled from the cooler, wilJiout 



EXTRACTION OF SUGAR FROM BEETS. 335 

Cooling causes the formation of crystals upon the sides 
of the moulds and the surface of the liquor. As soon as 
this crust of crystals has acquired some degree of consis- 
tency, it must be broken with a wooden spatula, and the 
whole contents of the mould carefully stirred, so as to col- 
lect in the centre the crystals that have formed upon the 
sides. When this has been done, the crystallization is al- 
lowed to go on undisturbed. 

Three days are more than enough for the formation of 
all the crystals ; * the plugs that close the points of the 
moulds are then taken out, and the moulds are placed in 
earthen pots, that the molasses may flow from them, t 

The crystals will be deprived of the molasses which 
unites them in about eight days ; the moulds are then car- 
ried into an apartment which, by means of a stove, is kept 
constantly heated to 18° or 20° of Reaumur, (izi72.5° and 
77° Fahr.) and there placed in fresh pots. 

The next operation is that of leaching the contents of 
the moulds, in order to obtain from them that portion of 
molasses which refused to flow out. For this purpose the 
surface of the loaves is carefully broken and scraped with 
the blade of a knife, so as to smooth it, and then there is 
thrown upon each one about half a pound of a white sirup, 
marking from 27° to 30°, (= specific gravity of 1.231 to 
1.261. 1 ) This sirup penetrates into the loaves, diluting 
and carrying ofl" the molasses, which is three or four de- 
grees more concentrated than itself If the concentration 
of the sirup were less, it would dissolve the sugar ; if it 
were more, it would render the sugar adhesive. This op- 

waitingf for the last product ; otherwise crystallization would be com- 
pleted in the cooler, and all the contents of it would forma mass 
which could not be poured into the moulds to extract from it the mo- 
lasses. 

* The operation may be known to be good, — 

1. When the surface of the crystallized mass is dry, so that, in pass- 
ing the hand over it, neither moisture nor adhesiveness is perceived. 

2. When the crust settles and breaks in the centre : in this case the 
refiners say the sugar makes a fountain. 

3. The yellow color of the crystals is generally a good indication, 
but in the case of beet sugar it is unimportant, because the color may 
have been blackened by the animal charcoal employed when the fil 
tration of the clarified liquor has not been carefully executed ; and 
this color is easily made to disappear by clarification and refinement. 

t These pots should be large enough to contain five or six gallons 
of liquor. 

X This sirup is only a portion of that which is prepared for boiling. 



'diiG rHYMISTUY AITLIED TO AGRICULTURE. 

oration is renewed two or three times at intervals of two 
days. 

When the loaves have remained a month in tlie stove- 
room, they can l>o taken out of the moulds ; they are then 
f nind to !)(' dry and entirely deprived of molasses, and are 
piled up in the store-house, where they are kept to be re- 
fmed. 



ARTICLE VII. 

On Boiling the Molasses and Leaching Sirups. 

I MIX the molasses obtained from the brown sugar with 
the sirups which have been filtrated through the loaves, 
and proceed to boil tlie mixture. The molasses marks 23° 
or 24°, (—specific gravity of 1.190 to 1.199,) the sirup 2V 
or 22°, (= 1.171 to 1.180,) and the mixture 22° or 23°, 
(= 1.180 to 1.190.) I throw from 32 to 35 gallons of this 
mixture into the boiler, and when the heat approaclies to 
ebullition, I add about one pound of animal charcoal, 
wliich I mix carefully with the lijjuor. 

The boiling of this liquor is more difficult tlian that of 
the sirup which produces the brown sugar, but with care 
and patience it may be done to very good advantage. This 
licjuor yields at least one sixth of the (piantity of sugar that 
has been procured by the first operation ; lliis product is 
sufficiently important to render it advisable to boil down the 
molasses, instead of disposing of it, as is almost everywhere 
done, for distillation. 

\'( the molasses procured from beets was of the same 
quality as that obtained from the sugar cane, it could be 
sold with advantage, but it has a bitter taste which renders 
it unsalable ; it is best then to exhaust it of crystalli/able 
matter, and to subject the remainder to distillation. The 
dilForence in the (piantity of alcohol obtained from the two 
kinds of molasses is almost nothing. 

Instead of depositing the product of this last boiling in 
moulds, I throw it, from day to day, into a hogshead open 
at one end, and thus gradually fill the cask ; the sugar 
crystallizes wonderfully in these vessels, so that they be- 
come half full of it. 



REFINING BEET SUGAR. 337 

When this sugar, which I call molasses sugar, to distin- 
guish it from the broivn sugar of the first boiling, is to be 
refined, the molasses which lies upon the top is dipped 
out, and the rest is made to flow out through small gimlet 
holes bored in the bottom and around the circumference 
of the cask. 

The sugar, when deprived of all the molasses which can 
be made to flow from it, still forms only an adhesive paste, 
which can scarcely be refined ; I therefore put this paste 
into bags of coarse, strong cloth, and subject it to a strong 
compression. The sugar thus freed from molasses is very 
dark colored, but the quality of it is excellent, and it is as 
easily refined as the best brown sugar. 

When the brown sugar boilings turn hadly, and crystal- 
lization in the moulds is imperfect, and, in a word, at all 
times when sugar is ropy, and parts but imperfectly with its 
molasses, it is necessary to subject it to the action of the 
press before attempting to refine it ; as soon as it has in 
this way been freed from all its molasses, it may be refined 
without any difl^culty.* 



SECTION III. 

On the Refining of Sugar obtained from Beet Roots. 

When the sugar is dry, the refining of it is easily per- 
formed ; all possible pains then should be taken in the pre- 
ceding operations to free it from all its molasses. 

All the operations of refining may be brought under two 
heads, clarification in the boiler, and whitening in the 
moulds. 

To refine sugar well, it is better not to operate upon too 

* In most of the beet sugar manufactories they have adopted the 
sw^inging boilers for preparing their sirups ; concentration is per- 
formed speedily in these, and they have the advantage of being emp- 
tied in a moment ; but they are useful only when the operation is 
performed upon dry sugars, like the American, which contain but lit- 
tle molasses. Our beet sugar is never so well drained as the imported 
sugars are, and requires much more care in the boiling. These boil- 
ers appear to me more apt to cause the burning of the sugar than the 
old kind, and I therefore give the preference to the latter. 

29 



338 CHYMISTHY AITLIED TO AORICfLTURE. 

larfife quantities. I hnve always observed that ulieii I sul)- 
jectrd to the same retiiiiiig process 'JOUO or iiOlM) lbs. of 
sugar, the last boilings were ropy, and each operation less 
p(?rt'ect than when j)prforined ujK)n 400 kilogrannnes (about 
81M)lbs.) at one time: it is upon tliis last quantity that 1 
shall found my calculations.* 



ARTICLE I. 



On Clarification. 



A BOILER four or five feet in diameter and twenty-eight 
inches in depth is two thirds filled with water, to which 
lime-water enough to till the boiler is added ; in this mix- 
ture is dissolved at a low heat 400 kilogrammes of brown 



sugar. 



The solution must not mark more than 3*2° (z= 1.280) 
of concentration ; if it stands higher, it must be weakened, 
*if lower, more sugar must be added. This state of con- 
centration belongs only to solutions of drv sugar ; those 
of damp sugar must be reduced to 30° or 25°, {=z 1.261 
to 1.210,) otherwise it will be almost impossible to filtrate 
them. 

The solution is then heated to ebullition. When the tem- 
perature reaches ().)° (z= 178^° Fahr.) fifteen kilogrammes 
(32^ lbs.) of animal charcoal are added to it; the mixture 
is then carefully stirred and mixed with a wooden spatula ; 
after allowing it to boil an hour, the fire is extiniriiished.t 
The boiling li(|uor is freed from the charcoal bv filtration 
through a coarse cloth, and when the heat has fallen to 
40°, (122° Fahr,,) the whites of fcjrty eggs beaten and 
diluted with several (piarts of water are thrown into the 

* I have nevpf boon able to nssijjn a ron.<?on for this difference, but 
it actually exi.sts ; p(Tliaj)S it arise.s rrt)iii inv not beiiiij able to com- 
plete Miy boilinirs in one day, and the claritied sirups liaving become 
chanjred in tlie boiler ; or j)erhaps a larjje (juantity of sirup n)ay be 
more difficult to niana^re tlian a small one, though the ingredients be 
combined in ibe same proportions. 

t The quantit)' of animal cliiirroal added ou^ht to vary according 
to the quality of the sugar ; that which is dry recpiiring a less portion 
than that which is wet. 



REFINING BEET SUGAR. 339 

boiler.* The liquor is then carefully stirred, and is kept 
constantly in motion till the temperature rises to 70°, 
(z= 180° Fahr.,) when stirring is omitted, and the heat 
raised to the boiling point. 

As soon as the first bubble appears upon the surface, the 
fire is extinguished ; a thick coat of scum forms upon the 
surface of the liquor, and is removed at the end of three 
quarters of an hour. 

The liquor is filtered through a coarse, thick, rough cloth ; 
if the first portion that passes through be not perfectly clear, 
it is to be thrown again upon the filter, and this operation is 
repeated till the liquor appears completely limpid and free 
from any floating particles. As soon as the liquor is perfect- 
ly clear, it is boiled ; five or six boilings being formed with 
the product of the clarification. 

The several boilings are thrown into the cooler as fast 
as they are completed, and from thence into the moulds 
four, which can contain 5^ gallons each. These opera- 
tions are conducted in the same manner as those which I 
have described in speaking of brown sugar, but with this 
difference, that the sugar contained in the moulds is stirred 
and moved at two different times before it is taken in the 
mass. 

After three days the moulds are placed upon the pots 
into which the molasses drains, and at the end of eight 
more, they are removed to the second pots, w^here the 
whitening is to be performed. 



ARTICLE II. 



On Whitening Sugar. 



The clarified sugar is dry, of a yellow color, varying 
considerably in the depth of its hue; the taste is mild 
and sweet. The process of bleaching removes from it the 

* I have noticed that the whites of eggs coagulate at a degree of 
heat between 30° and 35° of Reaumur, (= 122° and 133i° Fahr.) 
At that degree, I have proceeded to clarification. In some man- 
ufactories I have observed that the whites of eggs were added at 
the moment of ebullition ; but in this case they are immediately 
coagulated, and the clarification being only partial, the sugar comes 



340 CHYMISTUY Al'PLIED TO AGRICULTURE. 

small quantity of s^irup with which it is impregnated ; it 
can be etfected in three ways, namely, by the use of clay, 
of alc<)h(>l, and of tho sirups ; tlu; first of these is the one 
generally LMnjjloyt'd in liie refnieries. 

When sugar is to be clayed, a hogshead unheaded at 
one end and furnished with a row of stop-cocks placed one 
above the other from top to bottom, is partly filled with 
white clay, upon which water is poured till the cask is full ; 
the clay is then carefully stirred, so that every portion of 
it may be well washed. This operati(jii is repeated several 
times, the water of the washings being drawn off as soon 
as the clay settles, and a fresh quantity turned in, which 
is stirred in the same manner. 'The washing is continued 
till the water no longer appears charged with any foreign 
substances, when the water is allowed to remain undis- 
turbed upon the clay till this becomes thoroughly divided, 
so that uj)on handling it no lumj)s can be found. When 
the clay is found to be in this state, all the water is drawn 
off, and the clay suffered to dry gradually, till it acquires 
such a degree of consistency as not to flow when j)laced 
upon a smooth and slightly inclined board: it is now 
considered ready for use. 

Before j>l;icing the pre])ared clay upon the sugar con- 
tained in lAc moulds, the surface of the loaves is carefully 
scraped, so as to remove one layer of the sugar, which is 
replaced by a portion of very white jx>wdcred sugar ; this 
is piled up and smoothed very nicely, and then covered 
over with a layer of clay thrown on with a spoon. The 
water contained in the clay passes gradually into the layer 
of white sugar, which it dissolves, f(jrming a sirup which 
penetrates into the loaves, deprives the sugar of its color, 
and passes out at the jwint of the mould. 

The clay, being thus gradually deprived of water, shrinks 
and dries, and is then removed and thrown into the cask to 
be made use of in new operations. 

The upper part of the loaves is rendered white by this 
first oi)eration ; but when the liijuid which llows from the 
Oj)f:ning in the point of the mould is colored, a second 
claying is performed ; in this, however, the clay alone is 
used, the intermediate layer of sugar being dispensed with. 



out brownish, niid llioy arc then to be rrdissolved three or four times 
bolnro Ihoy att;iiii tlu* drsirrti drtrrro of whitonosg ; this occaaions 
much labor mui txj»onsp, togt-lher with a great loss of sugar. 



REJOINING BEET SUGAR. 341 

The number of clayings to be employed, depends upon 
the quantity of coloring matter contained in the sugar ; 
two are usually enough to render sugar merchantable ; 
but in order that the sirup may flow off free from any tinge 
of yellow, three must be employed. 

When the operation of claying is completed, the loaves 
are placed upon their bases, that the white sirup by which 
the points are softened may diffuse itself through the mass. 

At the end of eight or ten days the loaves are taken out 
of the moulds and placed in a stove-room, in which they are 
dried. 

The method of whitening by clay is certain, but it 
possesses the great fault of converting into sirup nearly -i- 
of the sugar operated upon ; and if the sugar is adhesive, or 
the grains of it very fine, the quantity of sirup formed is 
still more considerable. Whenever I have worked upon 
sugars of this description, I have melted them over, and 
freed them from their adhesiveness, by boiling them down 
with a quantity of animal charcoal. 

Brown sugar made from beets, when refined, generally 
yields in molasses or nonconverted sirup* between i and ^ 
of its own weight, and it loses by claying at least ^. 

The sirups which are produced during these various 
operations, are usually boiled without the addition of any 
foreign substance, and the product of these boilings is 
thrown from the cooler into the clemi-hdtardes, where they 
become crystallized ; these form the large loaves of sugar, 
M^eighing between 22 and 27 lbs. known in commerce 
under the name of lomhs. 

It has been attempted to substitute the method of 
w^hitening by alcohol for that by claying ; this process is 
founded upon the power which alcohol possesses, of dis- 
solving the coloring principle without acting upon the 
sugar. I followed this mode two months, niaking use of 
no other alcohol than what I procured from the distillation 
of my molasses. I confined myself in this process to 
leaching the loaves of sugar contained in my moulds with 
alcohol of 35° ( = sp. gr. 0.852) of concentration ; 
covering the moulds over so as to prevent loss by evapora- 



* The molasses or sirup which flows from the mould when it is put 
upon the earthen jar after cry&talUzation is called nonconverted sirup ; 
that which is procured by claying, converted sirup; the last is purer, 
lighter colored, and better tasted than the first. 
29* 



84S CHYMISTRY APPLIED TO AGRICLLTIUE. 

tioii, .ind renewiniT the alcohol till the liquor passed off 
|K?rrectIy clear from the jxiint of the mould ; this alcohol 
I redistilled, to employ in new operations. 

I abandoned this method of bleaching sugar for the fol- 
lowintT reasons. 

1. Notwithstanding all the precautions I took, I lost half 
a kilogramtne (a little more than a pound) of alcohol for 
each loaf of ten pounds' weight. 

2. The loaves of sugar, though well dried in the stove, 
always preserved a slight odor, which became more sensi- 
ble after their having been confined in the papers and 
transported. 

8. The price of alcohol of this degree of concentration, 
rendered the refining by alcohol as expensive as that of 
clay. 

Some very skilful chymi.sts propose to supply the use 
of clay by that of siruj) ; theory is in favor of this method, 
but experiment contradicts it. 

In the first place, in order that the sirup may be em- 
ployed with success, it is necessary that it should be white, 
and of course that it should be made by saturating water 
with very white, sugar. The water which is disengaged 
from the clay produces a sirup in passing through the 
layer of sugar with which the loaves are covered ; there 
is, therefore, no advantage to be derived from the use of 
sirup on account of its containing sugar, and the process 
is less economical than claying, inasmuch as both time 
and fuel * are required for making the sirup, whilst in 
claying it is produced by the process itself. 

However, as the theory is seducing, 1 tried this method, 
and the following statement exhibits the results. 

I prepared a quantity of sirup at 30° t ( := l.'2()l) of 
concentration, which 1 poured upon the smoothed surface 
of the loaves till they were covered with it; the following 
day the sirup had penetrated into the mass, which was 
sensibly whitened by it. I re})eated the oj)eration at inter- 
vals of f<:)ur hours, till the siruj) passed olf through the 
point of the mould clear ; this did not take place till the 

• I say furl, because water will not dissolve so much sugar by re- 
maining upon it at the tfiupcratun' of the ntinosplirro, but tnut it will 
take up still more in liltrating lliruuirh it; so as to increase in con- 
centration [i° or 4 '. 

t This is the point to which it is necessary to carry it, that it may 
not dissolve the sugar when cold. 



REFINING BEET SUGAR. 343 

end of twenty days, at which time the bleaching of the 
greater part of the loaves was completed. I continued 
the operation upon the others from twelve to twenty days, 
removing successively those that were finished. 

When I came to take these loaves from the moulds, they 
came out in fragments ; the sugar was moist and without 
consistency ; it was impossible to dry it, and I was obliged 
to melt it over and make double-refined sugar of it. I re- 
peated the operation of bleaching with sirup several times, 
and always obtained the same results. 

It is evident that the sirup applied in this manner inter- 
poses itself between the molecules of the sugar, and there 
remains ; whilst in the process of claying, the sirup, being 
formed gradually, passes through it by insensible filtration, 
imbibing the coloring matter, which it at length carries off. 
I moreover found that it required twice as much sugar 
to form the sirup as was needed in the usual method of 
claying. 

The numerous experiments which I have been in the 
way of making during a dozen years, have induced me to 
adopt a process which appears to me to be more advan- 
tageous than either of those of which I have just spoken. 
T cut out of the coarse cloth called calmuck, round pieces 
of the same size as the bases of the loaves ; these I soak 
in water and afterwards wring ; I then apply them care- 
fully to the bases of the loaves, which have been previously 
scraped and smoothed with the blade of a knife, or a small 
trowel. In twenty-four hours' time the surfaces of the 
loaves are bleached. I then pour upon the cloth about 
half a pound of the converted sirup of the last claying ; 
the sirup gradually penetrates the cloth, and filtrates 
through the loaves, from which it removes all the coloring 
matter. 

As soon as the sirup has passed through the cloth into 
the sugar, I moisten the cloth by sprinkling it with drops 
of water, and the next day I throw upon it the same quan- 
tity of converted sirup* 

This first operation is completed in five or six days, 
after which the sirup is left to flow during four or five days. 
By these leachings the loaves are perfectly bleached to 
the depth of four or five inches, but they are still a little 

* I here suppose that I operate upon moulds of four, the loaves 
from which weigh firom 11 to 14 lbs. 



344 ( HYMISTKY All'LIKI) TO AtJIlK ILTIUE. 

colored below; I coini)lete the bhsicliiiig by a sli^rht clay- 
inir, aj)j)lyiiig the earth immediately to the surface of the 
loaves without any iutormediate layer of sugar. 

I find that bleaching is performed more speedily and 
with less labor in this way ; the evils arising from the use 
of sirup alone are obviated, and but a small portion of 
t.ugar already bleached is dissolved. 

In order to appreciate all the advantages arising from 
well-conducted operations, it is necessary that one should 
know the cliange produced in suo^ar by repeated meltings; 
it is brou<'ht first to a [xiint when it will no longer crystal- 
lize, and afterwards to the state of molasses Sugar which 
lias been three or four times boiled over, will still crystal- 
lize upon the sides of the moulds, but the middle of the 
loaf will be only a uniform, thick, white mass, destitute of 
the agreeable taste of sugar ; this substance, if melted, does 
not again become solid, but remains in the state of mo- 
lasses. 

I ought to mention, that in the various operations that 
are performed upon sugar, the nature of the substance is 
often made to undergo a series of changes or a succession of 
degenerations ecjually constant and regular. 

I have just mentioned that when sugar is made to re- 
pass two or three times through the boiler, it is rendered 
uncrystallizable, and the middle of the loaf is found to 
consist of a uniform mass of the consistency of butter, 
not possessing the agreeable flavor of crystallized sugar. 
This mass, dissolved in water and concentrated by heat, 
is reduced to molasses; and when the evaporation and 
clarification of the juice of beets is prolonged beyond a 
certain time, nearly all the sugar is reduced to molasses, 
and the boiling is rendered long and ditHcult ; when this 
is the case, the sirup throws uj) an abundance of adhe- 
sive white foam, which, when removed with a skimmer, 
thickens and presents all the characteristics of vegetable 
wax. The experience of twelve years has uniformly fur- 
nished me with these results. 

I am thoroughly convinced that these alterations would 
be avoided by evaporating the sirup in a vacuum ; it has 
even occurred to me that the animal charcoal produced 
good effects only by its opjmsing the action of the oxygen 
of the atmosphere u|>on the sugar, since nearly the same 
results are obtained by the use of butter and other oily 
substances susceptible of extreme division. The secret of 



DISTILLATION OF BEET MOLASSES. 345 

causing this decomposition to retrace its steps, still remains 
to be discovered ; I have essayed it without success. 



SECTION IV. 
On THE Distillation of Beet Molasses. 

The molasses from beets, when exhausted of its sugar, 
has not the pleasant taste of that furnished by the sugar- 
cane, but retains a bitter taste which renders it fit only for 
distillation. 

The product in molasses is as great as that in sugar : 
each of the grandes-hdtardes in which the product of the 
first boiling is crystallized, yields 40 lbs. of molasses, and 
45 lbs. of brown or unrefined sugar : these 40 lbs. of mo- 
lasses, boiled over, produce 6 lbs. of sugar and 34 lbs. of 
molasses ; thus from two boilings are obtained 34 lbs of 
molasses, and 51 lbs. of brown sugar. 

As this sugar is not pure, it is necessary, in order to re- 
fine it, that it should be melted down, crystallized, and 
whitened. By these operations some molasses and some 
sirup is extracted from it. The molasses flows from the 
moulds when they are placed upon the jars, after the brown 
sugar has crystallized ; the sirup is formed during the pro- 
cess of claying ; this is boiled over to obtain the sugar 
dissolved in it, and the molasses remaining is mixed with 
that in the jars to be distilled. 

The weight of molasses obtained by these various ope- 
rations is nearly equal to that of the brown sugar. 

Supposing that I wish to produce the fermentation of 
445 lbs.* of molasses, to prepare it for distillation ; I pro- 
ceed in the following manner. I throw the whole quantity 
of molasses into a vat, and there add to it such a quantity 
of water as shall cause the liquor to mark 7° or 8° (=r 1.052 
to 1.060) of concentration. I stir the mixture with the 
greatest care, so as to unite the two fluids thoroughly. The 
vat is situated in an apartment of the manufactory, where 
the temperature is, by means of a stove, kept constantly 

* I usually operate upon 890 lbs. The vats in which fermentation 
is carried on contain 561 gallons. 



346 CHYMISTRY APPLIED TO AGRICULTURE. 

at 20" or 22^ (prol>:il)ly of lliauiimr,) (=z 77° and 88^" 
Falir.) and I take care that the hquor be raised to 15° or 
16°, (=: specific gravity of 1.1 1() to 1.125,) before the yeast 
is added to it. 

To make the leaven, whicli must be prepared on the 
morning of the day in uliich it is to be used, I form 25 
lbs. of rye nu'.il into a paste with molasses, and then dilute 
the paste with boiling water, to which 1 gradually add one 
quart of pure molasses, kneading the mass thoroughly till 
it is of the consistency of porridge : the heat of it in this 
state should be 20° or 25°, (=77° to 88° Fahr.) When 
this leaven is formed for a first operation, a little beer yeast 
or leaven of wheat Hour sliould be added to it. The bucket 
is covered over, and set into a place sufficiently warm to 
produce fermentation : the yeast soon begins to swell, and 
rises seven or eight inches in the bucket ; at the end of 
twelve or fourteen hours it is ready for use.* The yeast 
is thrown by small })ortions at a time into the vat, the 
liquor in which is stirred during the whole time. 

Fermentation conmiences in the course of two or three 
hours, and continues two or three days. 

The concentration of the liquid is gradually diminished, 
and at the end of the operation falls to 2°t, {z= specific 
gravity of 1.014.) 

The next process is that of distillation : the liquor is 
poured into the boiler of the alembic through a cloth 
strainer, by which all the meal and bran contained in it 
are separated ; without this precaution, the liquor would 
often ascend during distillation into the worm. 

Wlien distillation is carried on in the improved alem- 
bics, the first alcohol which passes marks 36° (:= 0.847) 
of the hydrometer ; it becomes gradually weaker till it 
stands at only 10° or 12°, (zir specific gravity of 1 .000 to 
0.987;) the operation is then arrested. The mixture of 
the products forms spirit marking from 22° to 25° (== spe- 
cific gravity of 0.932 to O.IUX).) 

The aft:er-taste of this spirit is so bitter as to diminish 
its value in commerce : I have been able to correct this 

• Bt'fore making use of tliis yeast, about ono sixth part of it is 
poured into a separate vi'ssel. to be u.-^ed in the next preparation of 
veaHt that may l»e needed ; so that in the subsequent operations only 
20 lbs. of meal an- required instead of li.") lbs. 

t Those substaiu-es foieign to the sarcharine prinrij)Ie contained 
in beel.s do not feriinnt ; they therefore prevent the degree of concen- 
tration from being less than '2°. 



DISTILLATION OF BEET MOLASSES. 347 

fault by mixing about 2^ lbs. of animal charcoal with the 
liquor of each boiling ; this is 90 gallons : the spirit ob- 
tained by this process differs but little from wine-brandy. 

I redistil nearly all the spirit over a naked fire, employing 
for it the same proportion of animal charcoal, and convert 
it into alcohol of 34°, (—0.858.) 

The sale of the alcohol is more easy and profitable than 
that of the spirit, as this quality of alcohol is in much re- 
quest amongst the manufacturers of colors for dissolving 
their resins. 

I once thought, that it would be more advantageous to 
leach the mash of the beets in order to mix the juice thus 
obtained with the molasses, and to ferment them together, 
but experience has undeceived me ; the juice ferments, and 
the molasses does not then undergo decomposition ; it is 
found in the boiler unchancred. I have found the same re- 
suits to be produced, when I have mixed the must of grapes 
with molasses. 

200 kilogrammes (445^ lbs.) yield upon distillation 
about 13 gallons of spirit of 22°, (z= 0.932;) these 13 gal- 
lons produce 6^ gallons of alcohol at 34°. The expenses 
of the operation may be calculated thus : 

One man, who conducts all the operations, and completes 
the distillation of it in one day, . 1 franc 50 centimes. 
Ten kilogrammes of rye, .... 1 

Pit coal, 3 

Animal charcoal, 50 



Total, 6 francs (= $1.14.) 

The conversion of this spirit into alcohol of 34° costs as 
follows : 

Day's wages, ... 1 franc . 50 centimes. 

Pit coal, .... 3 

Animal charcoal, . . 50 



Total, 5 francs 

From this it appears that the profits are not great, but 
distillation gives an actual value to molasses which is worth 
nothing. 



348 CIIYMISTRY APPLIED TO AGRICULTURE. 

SECTION V. 

On tuk Products of a Beet Sugar Manufactory.* 

In cstimatiii}/ the value of the products of a sugar man- 
ufactory, I will .suj)j)ose that 10,000 lbs. of beet roots are 
operated u|)oti each day ; however, as beets cannot be em- 
ployed till after they have been carefully trimmed, there 
is perhaps a loss of ^ part of that weight ; thus, in order 
actually to work upon 10,000 lbs. of beets, it is necessary to 
employ 12,000 lbs. so as to allow for this loss. 

The products of a sugar manufactory are of two kinds ; 
the first consists of the sugar, the second is furnished by 
the molasses, the mash, and the trimmings of the beet 
roots. 



ARTICLE I. 



Of the Product in Sugar. 

The product of the concentrated sirup obtained from 
10,000 lbs. of trimmed beets will fill eight moulds, each 
of which will contain 47 lbs. of good brown sugar ; this 
makes ...... 37G lbs. 

The molasses obtained from the moulds 
furnishes ^ as much sugar as is ob- 
tained by the first operation, equal to 62§ 



Total, 4:^^§ lbs. 
This quantity of brown sugar will, when refined, produce 
at least -^^V ^^ ^^^Y good double refined sugar; and y\^ 
of sugar of an inferior (piality obtained from the molasses 
and sirups ; the whole quantity of sugar being -j^j/j. 

According to this, the average quantity obtained by an 
operation skilfully conducted is, 

In sugar of the first quality, .... 187 lbs. 
In sugar of the second quality, ... GO 



Total. 214 IbH. 



* In llio cstinialo which follows, I have always valued the products 
at the lowest ral(.>, and the cxpcuses at the highest. 



PRODUCTS OF A BEET SUGAR MANUFACTORY. 349 

ARTICLE II. 

On the Secondary Products. 

The operations upon 10,000 lbs. of beets per day pro- 
duce, 

In mash, 2,511|^ lbs. 

In molasses, about 280 

The trimmings of 10,000 lbs. . 2,226 



ARTICLE III. 
On the Value of the Products, 

84 iif.ogrammes (187 lbs.) of good 

refined sugar, at 2 francs 5 centimes 

per kilogramme, 210 francs 

?J0 kilogrammes (60 lbs.) of middling 

sugar, at 2 francs 25 centimes per 

kilogramme, 67 50 



Total, 277 francs 50 
To give a value to the secondary products of the opera- 
tion upon 10,000 lbs. of beet roots, it is necessary to de- 
duce it from the price which they bear in commerce, or 
from that of the articles, the places of which they supply. 

1. I have estimated the weight of the trimmings of 
10,000 lbs. of beet roots to be 2,000 lbs. ; but these trim- 
mings contain nearly J- their weight in earth, and are fit 
only for feeding swine ; they v/ill supply the nourishment 
for twenty-five or thirty of these animals during the time 
that the operations upon the beets are continued. The 
value of the trimmings may be fixed at two francs and fifty 
centimes. 

2. The product in mash is far more valuable ; this sub- 
stance forms excellent food for animals, especially horned 
cattle : cows and sheep that are fed upon it give large 
quantities of milk. 

The mash contains about y^^y^^ of the nutritive principle 
of the beets, since only water and about y^^ of sugar or 
molasses can be extracted from them. 
30 



350 



ClIYMISTRY APPLIED TO AGRICULTURE. 



This article of food does not produce the same evil as 
dry fodder, which lessens the quantity of milk, and ob- 
structs the intestines of neat cattle, neither does it pro- 
duce the purtring and leanness, which are often occasioned 
by the use of green and watery herbage. 

The mash is prepared in winter, and it is at that season 
that animals experience the greatest need of this kind of 
food. 

One kilogramme of this mash and one quarter of a kilo- 
gramme of dry fodder, is more than enough to feed a 
merino sheep that gives suck. 

If the price of the mash is estimated at only twelve francs 
per 1000 lbs., the value of the mash each day will be thirty 
francs. 

3. As the molasses has no other value than that which it 
receives from distillation, it can be estimated only by the 
products of this operation ; and as the price of spirit varies 
greatly, it is impossible to settle it.* 

I do not think tiiat the value of the molasses should be 
estimated higher than nine francs for 50 kilogrammes ; 
10,000 lbs. of beet roots produce 130 kilogrammes; this 
is then an amount of twelve francs per day. 

Tabic of the Produrfs of the opr rat ions upon 10,000 lbs 
of li((t Roots per (lay. 



Nature of the Products. 


- 
Weight. 


Value. 


1. Refin'd ( 1st qunl. 
sugar, ( 2d qual. 

2. Trimmings 

3. Mash 

4. Molasses 

Total 


84 kilocrrammes 
30 ... . 

i.oon .... 

1,250 .... 
130 \ . . . 


210 frs. c. 
07 " 50 
2 ♦* 50 
30 " 
12 " 


2,494 kilogrammes 


322 frs. 



Whilst enumerating the products of beets, I have neg- 
lected one, which is however of some importance ; it is the 
leaves. As soon as the middle of August, tiie leaves may 
be trimmed otV to feed animals; at the season of digging, 

• Since my eBtablishmonl was formed, I hnve sold alcohol of 35<^ 
(= spfcifH' frravity of O.bolii) at various prices botsvcen 1G(J francs and 
500 Irancs j>er caak. 



EXPENSE OF A BEET SUGAR MANUFACTORY. 



351 



an immense number of cows and sheep may be fed for 
eight or ten days upon the leaves and necks that are cut 
off and thrown upon the ground. 



SECTION VI. 



On THE Expense of a Beet Sugar Manufactory. 



It is not enough to estimate the products of a sugar 
manufactory, in order to know whether the business can be 
carried on to advantage; a valuation of the expenses must 
likewise be made : in this, as in the foregoing part of my 
statement, I shall give only the results of my own experience. 

The expense of the necessary accommodations and uten- 
sils required for operating daily upon 10,000 lbs. of beet 
roots cannot be defrayed with less than 20,000 francs. 

If a permanent stream of water and a wine-press can be 
made use of, the expense may be reduced to 16,000 francs.* 

1. The principal article in the expenses of a manufactory 
of this kind is the cultivation of the bee+s. Estimating 
the price of 1,000 lbs. at ten francs, is placing it at a rate 
by which the manufacturer will escape injury .t 

* I do not include buildings, since such as are necessary for this 
manufacture are to be found almost every where. 

t If the proprietor of a manufactory should cultivate the beets him- 
self, sowing his fields with corn immediately after digging the roots, 
the expense of the preparatory ploughings performed in the winter 
and spring, and that of the manure and transportation, would be borne 
entirely by the crops of corn, and there would remain to the charge 
of the beets, which form an intermediate harvest, only the cost of sow- 
ing, weeding, digging, and transportation ; thus the price of these will 
be greatly diminished. 

It is easy to estimate upon this ground the cost of the beets to a 
manufacturer who cultivates them himself: I will here give the esti- 
mate of costs for a single acre. 

6 francs. 



rurcnase oi six puuiius oi seeu 
Sowing the same . . . . 


12 


Two weedings . . . . . 


. 22 


Digging 


. 20 


Transportation . . . . . 


20 


Storing . . . . . 


3 


Rent of the land . . . . 


40 


Taxes 


10 



Total, 133 franca. 
Estimating the mean product at 20,000 lbs., the cost to the farmer 



36'2 • HYMISTRY AI'l'LIED TO AGRICULTURE. 

Tims, ri,(H)0 lbs. ol' roolij hniujr made use of cncli day, 
in order that 10,000 lbs. may be prepared for the rasp, the 

cost will be 1'20 francs. 

'2. Tlie trimmini; oi' r^,000 lbs. at tlic 

rate of 60 centimes per 1,000 lbs. 

of trimmintrs, 7 20 c. 

3. Wagt's of eight women employed to 
tend the rasps, carry the beets, &lc. 

reckoned at (30 centimes per day, 4 SO 

4. Hire of man and two horses for the 
establishment, 7 2.> 

5. Two men for the presses, ... 2 fA) 

6. Inspector of the rasps and presses, 1 oO 

7. Two men to the l)oilers, ... 2 50 

8. 50 kilogrammes per day of animal 
charcoal, 1*1 

9. Value of coal consuined,* ... 25 

10. Salary of the head relincr, ... 5 

11. Salary of a second refiner, ... 2 2.5 

12. Lighting of the building, ... 1 50 



Total, 192 frs. 50 c. 

This list comprises only the expenses of a day's labor ; 
if the operations should be continued one hundred days, 
the expenses would amount to 19,2.50 francs. 

When the jiroparation of the juice and the manufactur- 
ing of the brown sugar are com])lcted, all the work people, 
excepting the two refiners, are dismissed ; these are enough 
for carrvini: on the operation of refininij. The expenses 
attendant upoti this last ojx'ration, which continues till au- 
tumn, are as follows : 

1. Waurs of the liead refiner, . . 1,000 francs. 

2. Wages of the second refmer, . 500 

3. Wages of a laborer, .... 25() 

4. For animal charcoal, .... 300 

of 1(M)() ll)s. is (I franrs, (m (MMitimos. Tlif cxpcnso of labor ajul ina- 
nun» an' horin' by tlie corn which is sown inuiu'diatdy after the dig- 
|riiijr of tb«' brt'Ls ; the crops of corn are improved by interposinj; the 
crof) of bei'ls betw»*en tluMU, as the earth is rendered hght, and the 
foMjuent weediritrs free the ground from all injurious plants. 

* This price is based upon the Kituatiou ot my own works in Tou- 
raine, two leagues distant from the miiu's : it must vary with the dis- 
tance and tile dilhculty of transportation. 



EXPENSE OF A BEET SUGAR MANUFACTORY. 353 

5. For pit coal, 700 

6. For whites of eggs, .... 100 

7. For pipe clay, 50 

Total, 2,900 francs. 

To these expenses must be added the following : 

1. Interest of the funds employed in 

furnishing the manufactory, .... 1,200 francs. 

2. For repairing and replacing uten- 
sils of all sorts, 1,500 

3. For purchasing bags, strainers, 

and other small matters, 700 



3,400 francs. 
Thus the actual amount of expenses of all 

kinds attendant upon working 1,200,000 

lbs. of beets, amounts to 25,550 francs. 

I have already proved the product per day 

to be 322 francs ; this would give, for one 

hundred days of effective labor, . . . 32,200 

This allows to the manufactory a profit of 6,650 frs. 

The calculations are exact, and deduced from the results 
of a well-conducted process. A variation from them can 
only be produced by local situations. But experienced 
agriculturists will perceive, that I have placed certain 
expenses at the highest rate, whilst some of the receipts 
are estimated at the lowest. There are but few sections 
of France, where pit coal is as dear as it is in Touraine, 
where my establishment is situated. There would be, 
almost everywhere else, a considerable saving in this arti- 
cle. I have rated the value of the mash only at 12 francs 
per 1,000 pounds, although it is very nearly as valuable 
for feeding animals as an equal weight of dry fodder. I 
have estimated the price of the roots at 10 francs per 
1000 ; but this is more than they would cost a landholder, 
especially if he should sow corn immediately after the 
beets are dug. I have set no price on the leaves of the 
beets, and yet these will furnish food for the animals of 
the farm from the middle of August till the end of Octo- 
ber. 

But, whatever profits this manufacture is capable of 
affording, it must always be remembered that a want of skill 
30* 



354 CHYMISTRY APPLIED TO AGRICULTURE. 

in tlic operations, or negligence in the preservation of the 
roots, nmst occasion some losses in an nndertaking, which, 
even at the low j>rice at which I have estimated sugar, 
promises sullicienl renmncration in the hands of an intelli- 
gent man. 



SECTION VIL 
General Considerations. 

From twelve years' experience I have learned, in the 
first place, that the sugar extracted from beets differs from 
that of the sugar-cane neither in color, taste, nor crystal- 
lization ; and, in the second place, that the manufacture 
of this kind of sugar can compete advantageously with that 
of the sugar-cane, when the price of this last is in com- 
merce one franc and twenty centimes per demi-kilogramme 
(rr \S^ cents per pound.*) 

These facts being established and acknowledged, it may 
be asked whether the manufacture of beet sugar would be 
advantageous to agriculture. 

The cultivation of beets will not prevent the production 
of a single kernel of wheat, since this may be made an in- 
termediate crop, and the sowing of it commenced as soon 
as the beets shall be dug. The crops of corn are better 
u|)on these lands than upon others, because the beets have 
divided and loosened the earth, and the weedings have 
cleared it of strange plants. 

* It is objoctod, that beet sugar of bad <iuality is thrown into tlie mar- 
ket. I do not contradict the fact ; but it only proves that the suijar 
was badly made. Diirinir ten years, the sugar from my manufactory 
has been sold at tlje same j)rice as that i'rom thr suirar-eane of the 
same degree of rrfuicment ; and not tbe slightest dilfrrcnce between 
the two has ever been perceived. 

[t is said, that the great<'r part of the establishments of this kind 
have b«*en given up, atler having occasioned loss to the proprietors. 
Tbi.s. al.so, is a fact wiiiclj 1 shall not disptil*'. Hut I must remark, 
that this new branch of industry, like all others, requires some knowl- 
edge and apprenticeship. It needs to be conducti-d by men accus- 
tomed to similar operations ; and it is not at all surprising, that these 
liave not been rvcrywhere found. 

It is impossible to mention any kind of manufa«;ture amongst thoM 
that have succeeded, where perfection has been attained at ouce. 



(SfiNERAL CONSIDfiRATlONS^ 055 

The operations upon 10^000 pounds of beets per day, 
place at the disposal of an agriculturist about 1250 kilo- 
grammes (=: 1^ tons) of mash, which is the best kind of 
food for horned cattle. 

The working of the beets being performed in winter, 
furnishes employment to the men and cattle of a farm, at 
a season when they are too often condemned to idleness. 

Finally, if the manufacture of sugar from beets should 
be carried to such an extent as to furnish a supply for all 
France, agriculture would receive from it the value of more 
than 80,000,000 francs per annum. 

The prosperity of an establishment of this kind, depends 
upon its being connected with rural labors. This kind of 
manufactory is out of place in towns, because buying beets 
is much more expensive than raising them, the mash can- 
not be rendered productive, labor and fuel are more expen- 
sive, and there is not, as upon a farm, a supply of labor 
both of men and animals. 

But can this manufacture be reconciled with the interests 
of our colonies? 

Before the revolution, this would have been a difficult 
question to answer. Then, our colonies not only supplied 
our own wants, but furnished an overplus worth about 
80,000,000, which we exported to foreign countries, partic- 
ularly to those of the north of Europe. From these we 
received in exchange timber, iron, copper, hemp, tallow, 
tar, &c. The loss of our principal colonies has caused this 
important trade to pass into other hands, and those colonies 
that remain to us do not furnish sugar enough for the con- 
sumption of our own country. 

The government has, at this time, two ends to attain, 
one of which is, the advancing of the welfare of our colo- 
nies, and the other, the encouragement of the manufacture 
of beet sugar. Both would be accomplished by prohibiting 
the importation of foreign sugars. When this is done, the 
suD-ar of our colonies will find an advantageous market, 
and the manufactories of beet sugar will increase in num- 
ber. 

Supposing the wants of France should be supplied by 
the sugar from beets, — could we not then resume our com- 
merce with foreign nations, by means of our colonial sugar ? 
France would, at the same time, be safe from the danger of 
privation, and from those variations in price which are pro- 
duced by a maritime war. 



356 



CHYMISTRV APPLIED TO AGRICULTURE. 



It is a fact that if the government do not interest itself 
seriously in tills important sul)j<'ct, neither tlie colonies nor 
the manufactories will ever acquire a great degree of pros- 
l)erity : and one of the finest discoveries of modern times 
will be lost to France. 






JLIBR 



INDEX. 



Acid, carbonic, (gas,) one of the fluids contained in the atmosphere , 
its proportion to azote and oxygen,!. — Its absorption by the leaves 
of plants, 2, 5. — Its combination with lime, 5, 32. — Its solution in 
liquids, 5. — Produced by germination, 77,78. — Its influence upon 
the nutrition of vegetables, 80. — Its decomposition, 81. — Furnished 
by ripe fruits, 87, 88. — By leaves, fruits, and roots, 132. 

Acids, vegetable, their differences at different periods of vegetation ; 
those most abundant, 159. — Processes for extracting them, 162 et 
seq. — Their uses and properties, ibid. 

Affinities, laws which affect bodies, 3 et seq. 

Agriculture, its importance, xi. — Its progress, xii. — Its wants, xiii. 
— Conditions necessary to hasten its progress, xxi. — Interests and 
duties of government, ibid. — Foreign products which it may yet ap- 
propriate ; table of the products of French agriculture, 131. 

Air, its action upon vegetation, upon diff"erent soils; what it supplies 
to the plant; its action upon dead vegetables, upon fruits, 21-41. 

Albumen, its existence in many vegetables, 154. — Its uses, its analy- 
sis, 154, 155. 

Alcohol, a means of preserving animal substances from putrefaction, 
202, 270. — Of hydrometers, 269. — Alcohol from cider, 270. — From 
wild cherries, ibid. — From molasses, ibid. 

Alkalies, fixed, 168. 

Alumina, enters into the composition of arable soils, 18. — Is abundant 
in clays, 27. — Process for obtaining it pure, 31. — Its specific gravi- 
ty, ibid. — Its properties and composition, ibid. — Its action upon 
water, 35. — It combines with oils, 39. 

Ammonia, 62. 

Animals, number of animals employed in French agriculture, 132. 

Ashes, of mould, 17. — Action of the ashes of turf and pit coal as ma- 
nures, 76. — Effects of the ashes from our domestic fires, 76, 77. — 
The ashes obtained from different vegetables, table of experiments 
xnade, 170. 



358 INDEX. 

Azote, one of the fluids composing the atmosphere, 1,7. — Its propor- 
tion, influence, and properties, 2. — Its specific gravity, i6ui. — Its 
influence upon vegetation, 92. 

B. 

Beer, a refresliing drink, 279. 

Beet, ita cultivation, 315. — Choice of seeds, 316. — Choice of a soil, 
317. — Preparation of the soil, 318. — Method of sowing, 319. — Care 
during vegetation, 320. — Pulling, 321. — Preservation, 322. — Ex- 
traction of the sugar, 324. — Picking, ibid. — Rasping, 32.5. — Extrac- 
tion of the juice, ibid. — Clarification, 327. — Concentration, evapora- 
tion, 330. — Boiling of the sirups, 331. — Boiling of the molasses and 
leaching sirups, 33C. — Refining, 337. — Clarification, 338. — Bleach- 
ing, 339. — Distillation of the molasses, 345. — Product of a sugar- 
house, 347, 348. — Product in sugar, 348. — Additional products, 348, 
349. — Table of products, 350. — Expenses, 351. — General consid- 
erations, 3.54. 

Bones, an active means of fertilizing lands, 58. — Their composition, 
reduction to powder, uses, 59. — Advantages afforded by them, 76. 

Buildings, in the country, means of rendering them healthy, 283. — 
Necessary conditions, 284. — Choice of a situation, 284, 285. — Pre- 
cautions to be observed, 285. — Purification of stables and sheepfolds, 
286 et scq. 

Burning, of a soil, 114. — Its utility, and inconveniences, 115. 

Butter, one of the elements of milk, 208. — Mode of obtaining it, 210. 
— Its color, ibid. — Its becoming rancid, 213. — Means of preserv- 
ing it, ibid. 



Caloric, one of the fluids existing in all bodies, 1. 

Calou, a drink, 279. 

Canals, advantages of them, xxv, 237. 

Carbon, 17. — Its combination with oxygen, 87. — Supphed by leaves, 
fruits, and roots, 133. 

Carbonate, state of lime in soils devoted to cultivation, 32. — Carbo- 
nates of lime and magnesia, 47 et seq. 

Carbonic acid. See Acid. 

Chalk, preserves animal and vegetable substances from too rapid a 
decomposition, 39. — Suitable to argillaceous soils, ibid. 

Cheese, 20H, 221. 

Chica, a drink, 27!>. 

Chlorine, utility of fumigations with it, in purifying dwellings, 288. 

l^nYMisTRv, its progress, xiv, xvii. — Limits which it has not yet been 
able to pass, xviii, lix. — Its application to agriculture, xix, ix. 



INDEX. 359 

Clays, their nature, 27. — Unproductive, whatever may be the 

cause, 28. 
Clearing of lands, xxiii. 
Composts, how formed, 64, 65. 
Cream, its nature, preservation, uses, 208, 209. 
Crises, manufacturing and commercial, less numerous in France than 

in England, 223. 
Cropping, explained, 120, 121. — Principles which should guide the 

agriculturist, 121, 124. — Examples of cropping upon compact soils, 

130. — Upon light soils, ibid. — Upon siliceous soils, ibid. — Upon 

soils suitable for wheat, 131. 

D. 

Dews, more abundant in the south than in the north, 33. — Their ef- 
fects, ibid. 

Distillation, 252. — Processes of the ancients, 2-52, 253. — Its prog- 
ress, 254. — Different methods, ibid. — New processes, 259-262. — 
Variety of apparatus for distilling, 263. 

Division of landed estates, xxx. — Division of the soil into small es- 
tates, 226 et seq. 

Domains to be devoted to agricultural instruction, 233. — Various 
qualities which the soil should possess, ibid. 

Drinks, for the use of common people ; means of rendering them 
healthy, 271 et seq. — Fermented, 273. — Method of preparing them, 
274. — Vinous, cdWed piquettes , 275. — Their utility, 276. — Obtained 
from the sap of trees, 279. — Mode of making calou^dX Coromandel, 
ibid. — Of making chica, in America, ibid. — Of making quass, in 
Russia, 280. 

Drying, employed as a means of preservation, 183. — Processes, 184 
et seq. 

Dung, its properties, 64. — Salts which it contains, ibid. — Adaptation 
of it to each variety o? so\\,ibid. — Fowls', 61. — Night-soil, zJi^Z. — 
Lands and plants to which it is suited, ibid. — Perfection of this 
branch of business in Belgium, 62. 

E. 

Earths, their nature, action upon vegetation, 14. — Principles to which 
they owe their fertility, 17, 18. — Formed by the waste of mountains, 
19, 20. — Origin of the earths which cover the table-lands of moun- 
tains, 21. — Actual composition of arable soils, 19. — Those earths 
which can pass into plants, 26, 27. — Their properties, 30. — Those 
best suited to absorb moisture, 35. — Analysis of them, 44. — Their 
desiccation by fire, 45. — Dissolved by acids, 46. — Of earths, salts, 



3G0 INDEX, 

animal and vegetable bubstanccs, 40, 47. — Magnesian eartlis, not 
very fertile, 72, 73. 

Electricity, an imponderable fluid, 8 et seq. — Il» influence upon 
vegetation, ibid. 

Encouragement which the government ought to grant to French 
agriculture, !2:W. — Useful associations, ibid. 

EsTATKS, if the division of them be beneficial or injurious, 197. — 
Where it should stop, 225. — Of large and small estates, 224. — Ad- 
vantages lesulling from the liberty of acquiring landed property, Und. 

EXCIIAN(.ES, XXV. 



Fallow lands, causes which have perpetuated them, 117. — Preju- 
dicial to the interests of agriculture, 117, 118. 

Fekme.ntation, general views, 238, 239. — Alcoholic, 239. — Of 
leaven, ferment, or yeast, 240. — Of the must of the grape, 241. — 
Improvement in the processes for making wine, 243, 244. — Fermen- 
tation of grains, 248. — Of potatoes, 248, 249. — Of the mash of 
grapes, 275. — Of apples and pears, 27G. — Of cherries and mazzards, 
277. — Of the berries of the service-tree, 278. — Of plums and figs, 
ibid. — Of juniper berries, ibid. — Of the sap of trees, 279. — Of 
barley and rye, ibid, ct scq. 

Fibre, vegetable, analysis of it, 14!>. — Use made of it in manufac- 
tures, 150. — Methods of reducing it to charcoal, 152 ct seq. — Uses 
of charcoal, 153, 154. 

Filtration of water, 273. 

Flax, the soaking of it in water, 150. — Opinions respecting tlie ma- 
chines substituted for the action of water, ibid. 

Flint.s, or pebbles, efll'ct of mixing tlieiii witli arable soils, 40. 

Fluids, contained in the atmosphere, 2, 8, et seq. 

Fore.sts, means of encouraging the planting and preservation of 
them, xxiv. 

Fructification, 95, 90. 

Fruits, 86. — Ripening of them, 87. — Mode of preserving them, t6u/ 
— When ripe, yield carbonic acid, 87, 88. 



Gas, carbonic acid. See Acid. — Azote and oxygen, 1, 2. 

Gelatine, its decomposition in earth, its solution in water, 59. — 
Abounds in the horns and hoofd of animals, GO. 

Germination, 77. 

Gluten, a vogeto-animal principle, 154, 155. — Its existence and pro- 
portions in wheat, 150. — Its influence upon clarification, 159. 



INDEX. 361 

Grains, means of preserving them, 190. See Trenches. 

Gravel, its presence necessary in a good soil, 26. — Utility of mixing 

it with impoverished soils, 26, 27. 
Gums, their nature, 135. — Their use in the arts, 135. — Employed as 

food, ibid. — Analysis of them, 136. 

H. 

Heat, its effect, xv. — Its influence upon bodies, 9. — Unequal propor- 
tion of this fluid in bodies, ihid. — Phenomena produced by its emis- 
sion and absorption, ibid. — Its efiects, dilation, fluidity, motion, 11. 
— Combustion of vegetables in large masses, 15. — Its action upon 
the plant, 36. — Upon animals, ihid. — Diflerent upon different soils, 
ihid. — Developed more or less by manures, 37. — Its influence upon 
germination, 77. — Upon vegetation, 58 et seq. 

Horns, their effects as a manure, 60. — The advantages of employing 
them, 76. 

Hydrogen (gas), 15. 

Hydrometer, 269. 

I. 

Implements of Husbandry, comparison of tillage performed with the 
hoe, spade, and plough, 107. — Use of the harrow and roller, 108, 109. 

Indigo. See Woad. 

Instruction, special, in agriculture ; its necessity and utility, 233 etseq. 

Irrigation, its use according to the nature of soils, 116. — Times most 
favorable to it, 117. 



Lamp-black, 149. 

Laws called for by agriculture, xviii et seq. 

Leases, inconveniences resulting from their short duration, xxxiv. 

Leather, 158. 

Leaves, principal organs of nutrition, 35 et seq. 

Ley-washing, cleansing offabrics of hemp, &c., 289. — An economical 
liquor for supplying the place of soap ; mode of using it, 290. — Ap- 
paratus for whitening household linen, 290. — Processes for whiten- 
ing cotton thread, 290. 

Life, agricultural, preferable to a manufacturing life, 223.' 

Light, one of the fluids diffused through the atmosphere, 1. — Its influ- 
ence upon vegetation, 12, 13. — Upon germination, 79. — Upon nutri- 
tion, 81. — Necessary to the giving out of oxygen gas by leaves, 101. 

Lime, enters into the composition of arable soils, 18. — Deprives the air 
of its carbonic acid, 21. — Process for obtaining it pure ; its properties, 
31 



362 INDEX. 

;^2 — Absorbs water, ihul. — What limrstone loses by calcination, r>8, 
Gl'. — Air-slack»'(l ; its uses inairriculture,(»i>. — Dangerof using quick- 
lime, »Z»/<i. — Its combination with veg<'table and animal 8ubBtance8,G0, 
70. — Its action upon lands, 71. — Mode of employing and preparing 
it, il/itl. — Presence and eflects of magnesia in calcareous rocks, 7)i. 
— Use of lime for the purification of sheep-folds, HG, 87. 
LiQuoR.s, alcoholic, method of making them, 201, 202. 

LlTIIARGK, 145. 

M. 

Magnesia, sometimes enters into the composition of arable soils, 18. 
Manures, XXX, 41). — Their nature and action, 4'J, 50, CO. — Diiference 

between nutritive and stimulating manures, 75, 76. 
Manuring, the process, lOG. — Its effects, 107. — Varied according to 

ihe nature of the soil, 109. 
Marl, its composition, 28. — Its properties, qualities, mixtures with 

other substances, 20. 
Ml I, K, 207. — Principles which it contains, and modes of separating 

them, 21 1 . — Goats' milk, ibid. ^Woman's milk, ibid — Asses' milk, 

212. — Mares' milk, ibid, et seq. 
MixTiKK of earths, 2G, 27. — Their properties, 38. — Of chalk, silex, 

alumina, 38, 39. 
Moui.i), its formation, 15. — Principles which it contains, ibid. — Product 

of its distillation in a retort, 16. — Its decomposition, 17. — Its ef- 
fects upon vegetation, 3G, 81. 
Mountains, their decomposition causes the formation of arable lands, 

19-23. 
Mucilage, r.i5. 

N. 

Nations, agricultural and manufacturing; differencebetweenthem,221. 
Nutrition ok Plants, its operation, 80 et scq. — Summary of the 
phenomena attending it, W ct seq. 

O. 

Oils, their character ; fixed and volatile, 142, 1 43. — Mode of extracting 
them, 143, 144. — Processes for purifying them, ibid. — Fixed oils 
combined with metallic oxides, 144, 145. — Their uses, 145. — Vola- 
tile oils, 14G. — Plants which furnish them, 146, 147. — Their uses, 
ibid. 

Oxygen (gas), forms one fifth part of the atmosphere, 2 et seq. — One 
of the elements of vegetable productions ; principal agent of germina- 



INDEX. 363 

tion, 77, 78. — Plants which absorb the largest proportion of it, 83, 
84. — Its action upon fruits, 85. 



Plaster, employment of it as a manure, 72, 73. — Its composition, 73. 

— Use of crude and baked plaster compared, 74. — Its effects, ibid. 

— To what its action is to be attributed, ibid, et seq. — Its solubility 
in water, 75. — Its influence upon the quality of salts, 69. 

Potash, how extracted; its use, 168, 171, 172. — Table of the re- 
sults obtained by its extraction from different vegetables, 171. — Its 
analysis, 173 et seq. 

PouDRETTE, its good effccts as a manure, 63. 

Preservation, causes which affect the deterioration of animal and 
vegetable substances, 182. — Means of preserving them, 183. 

Prizes, should be offered for the encouragement and furtherance of 
agricultural science, 234 et seq. 

Q. 

QuAss, a drink, 280. 

R. 

Resins, 147. — Sap of trees, ibid. — Means of obtaining them, 148. — 
Their uses, 148, 149. 

Roads, district, necessity of a law relating to them, xxiv. 

Roots, one of the organs of nutrition of plants, 80. — Juices and salts 
which they draw from the earth, ibid. — Portion of oxygen which 
they absorb, 84. — Absorb the oxygen which exists in water, 84, 85. 

S. 

Salting, a means of preserving meats, 202. — Different methods, 203, 
204. — Salting of butter, 206. 

Salts, their influence upon vegetation, 41. — Their chymical action, 
ibid. — Means of knowing the quantity of them in soils, 48. — Prop- 
erties and characteristics of nitre, of marine salt, of sulphate of soda, 
48, 49. — Absorption of them by plants, 66, 68. — Abundant in herba- 
ceous plants, 98, 99. — Suitable to argillaceous soils, 110. — Those 
most common in vegetables, 175. — Those most proper for salting, 
202. — Disastrous tax on salt, xxviii. 

Sap, influence of temperature upon it, 104, 105. — Its elaboration in 
vegetables, 134. — Use made of it in various countries for making 
drinks, 279. 

Sheepfolds, 286. 



'U\\ INDEX. 

Si I, HA, enters into the composition of arable soils, 18. — Its mixture 
with alumina, i7*i</. — Trocess lor obtaining it pure, 30. — Abundant 
in vegetables, 31. — Properties, 35. 

SiRiPs, processes for making them, l"?. 

Soda, extraction of it from marine plants, 173. 

Soils, tlieir nature, tlicir elements, 18, 19,23,24, 25. — Mixtures of 
them, 27, 28. — Their fertility, as affected by their composition and 
exj)osure, 40, 41. — Exhausted by long cultivation, IJO. 

Stables and Sheepfglds, purification of the air in, 280. 

Starch or F'ecula, 13C. — Its u.sc, 13G, 137. — Process for obtaining 
it, 137 et arq. 

Straw, a weak manure, 63. 

Sugar, to what the name is applied, 140. — Three kinds known, ibid. 
— Vegetables which yield them, 140, 141. — Their specific gravity, 
141. — Extraction of sugar from beets. See Beet. 

ScLPHLR, fumigation with it for ])urifying sheepfolds, 280. 

Sweat, animal, 01. — its analysis, ibid. 



Tannin, its characteristics, proper uses, and the mode of extracting it, 
158. — Improvement of the art of the tanner, 158. — Combination 
of tannin with gelatine, 203. 

Tar, how o'wiuined, 148. — Process for improving it, ibid. 

Tax, upon salt, a public calamity, xxvii. 

Temperature, its variations and effects, 11, 12. 

Tillage, its advantages, varieties, appropriate periods, depth, accord- 
ing to the nature of soils and plants, 42. — Soils which require more 
or less tillage, 107, 108 ct seq. 

Trees, resinous, 147, 148. 

Trenches, suited to the preservation of grains, 190, 194. 

U. 

Urine, as a manure, 57. — Varieties in the urine of animals, ibid. — 
Its efficiency in composts, 58. — Its combination with plaster and 
lime, ibid. 

V. 

Vapors, aqueous, their effects, 32, 33. 
Vegetable acids. See Acids. 
Vitality, its laws, xviii. 



INDEX. ^65 



W. 



Water, one of the fluids diffused through the atmosphere, I. — Its va- 
riations and effects, as modified by temperature, 7. — Its passage into 
the state of ice, 21. — Its action upon vegetables, 33. — Its absorp- 
tion by soils, 34. — Concurs in germination, 77, 78. — Its influence 
upon the nutrition of plants, 89. — Properties of different waters, 
89, 90, 91. — Serves as a vehicle to the air, 92. — Hastens the fer- 
mentation of manures, 116. — Its different states in the plant, 201. 

— Different qualities of well-water, 271. — Cistern- water, 272. — 
Water of pools, ibid. — Filtration of water, 273. 

Wax, exists in some plants, 141. — Its extraction, iJi<Z. — Its use in 
the arts, ibid. 

WoAD, 294, 295. — Extraction of indigo from woad ; variation in the 
coloring principle, 297. — Gathering of the leaves, 298. — Manufac- 
ture of the cakes, 300 et seq. — Refining, ibid. — Dying of stuffs, 
301. — Means of improving the process of extracting the indigo, 303. 

— Establishments at Albi, 303. — Difference in the indigoes obtained, 
304. — Process, ibid, et seq. — Of beating, 307. — Of precipitation, 
ibid. — Of washing, 309. — Drying, 311. — Sweating, ibid. — Esti- 
mates of the product, 312 et seq. — Encouragement desirable, 314. 

Wool, refuse, employed as a manure, 60 et seq. 

Workshops, which should be united to an establishment for special 
instruction, 232. 



m 



\J 



